Initial commit — multi-provider + SMTP plans

keysat-smtp-emails.md

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+# Keysat email integration — operator alerts + buyer transactional emails
+
+## Context
+
+Today Keysat does NOT send any email. The architecture is deliberately
+delegation-only: every notable event fires a signed HMAC webhook to whatever
+endpoints operators have configured (`webhook_endpoints` table), and the
+operator's app decides whether to render that as an email, push, in-app
+banner, Slack DM, etc. The renewal-worker comment in `subscriptions.rs`
+makes this explicit: *"Keysat does not email buyers itself — operator-driven
+communication, same as license issuance."*
+
+Two cases push against that stance:
+
+1. **Operator-facing operational alerts.** When something goes wrong INSIDE
+   Keysat (Zaprite auth dies, webhook deliveries to the operator's own
+   endpoint fail 25 times in a row, the master Keysat license is about to
+   expire) — the operator needs to know NOW. Webhooks are the wrong channel
+   because the operator's webhook receiver is itself part of what might be
+   broken, and the operator doesn't have a separate "Keysat health monitor"
+   service waiting to act on these. Email straight from Keysat to the
+   operator, via StartOS SMTP, is the right channel.
+
+2. **Buyer-facing emails when Keysat IS the brand.** The master Keysat
+   instance (running at keysat.xyz, selling Keysat licenses themselves) is
+   the one operator that legitimately wants Keysat-branded buyer emails —
+   the buyer is buying Keysat, so the email should come from "Keysat
+   support." Most operators (selling Recaps, etc.) should NOT have Keysat
+   send buyer emails — their buyer relationship belongs to their own brand
+   and their existing email pipeline. So this needs to be opt-in per
+   **merchant profile**, with sensible defaults (off everywhere except the
+   master Keysat profile).
+
+The plan implements both, with clean separation between the two audiences
+so future operators can opt into one without the other.
+
+## Dependency on the merchant-profile model
+
+This plan composes with `multi-provider-payment-model.md` (the
+merchant-profile foundation). Per-merchant-profile SMTP override fields
+already land in that plan's `merchant_profiles` table (so a Pro/Patron
+operator running 3 businesses can send each one's buyer emails from a
+different domain with proper SPF/DKIM/DMARC). The per-business email
+branding fields (`sender_name`, `reply_to`, `support_url`, `brand_color`)
+also live on merchant profiles, not products.
+
+**This plan's scope is therefore:**
+- The `notifications` module + StartOS SMTP wiring + the `Send test
+  email` UI (Phase 1 below).
+- The operator-alerts module + Tier-1 alert call sites (Phase 2).
+- The buyer-email infrastructure + templates + per-profile opt-in flag
+  + per-event-type opt-outs (Phase 3).
+- Flipping the master Keysat profile's flag to ON (Phase 4).
+
+**It assumes the merchant-profile migration has already shipped.** If
+that order flips (we want to ship some email work before
+merchant-profiles), the schema in this plan would need to be temporarily
+on `products` instead, with a follow-up migration to move to
+`merchant_profiles` later. That's mechanical but ugly; recommend
+shipping merchant-profiles first.
+
+## High-level shape
+
+- **New `notifications` module** (`src/notifications/mod.rs`) — provider-
+  agnostic interface (`send_email(to, subject, body)`), implemented against
+  StartOS SMTP. Future-extensible to other channels (Slack, Discord, etc.)
+  if any operator ever asks.
+- **New `operator_alerts` module** — fires `notifications::send_email` to
+  the operator's address whenever a tracked system-level condition trips.
+  Always on; no opt-in. Recipient = operator's email from StartOS or a
+  Keysat setting.
+- **Extension of the existing webhook-dispatch path** to ALSO send a buyer
+  email when a per-merchant-profile `keysat_sends_buyer_emails = true`
+  flag is set AND the event type is in the buyer-relevant set. Default
+  off everywhere except the master Keysat profile (Pro/Patron tier
+  required to flip it on for non-master profiles).
+- **Template system** — markdown/HTML templates per event type, with
+  per-profile override fields already on `merchant_profiles` (sender
+  name, reply-to, brand color, support URL, custom intro paragraph) so
+  even Keysat-direct emails are sent from the right business with the
+  right branding for each profile. Default templates use the merchant
+  profile's `name` field.
+
+## StartOS SMTP integration
+
+StartOS exposes operator-configured SMTP credentials at the OS level so
+services don't each have to re-prompt for them. Verify the exact shape
+before coding (read StartOS 0.4.x SDK docs + look at how an existing
+StartOS package consumes SMTP — `hello-world-startos` or `nostr-rs-relay`
+likely have examples).
+
+Expected shape based on StartOS 0.4 conventions:
+
+- StartOS exposes SMTP host + port + username + password + from-address
+  via either an env var injected into the package's container OR a
+  read-only API call to the host (`start-cli system smtp get` or similar).
+- The `start-sdk`'s TypeScript layer (in our `startos/main.ts`) is the
+  right place to read and pass them through — either as env vars set on
+  daemon startup or as a generated config file mounted into `/data/`.
+- Keysat daemon reads them at boot, holds them in `AppState::config.smtp`,
+  every `send_email()` call uses them.
+
+**Behavior when SMTP isn't configured** on the StartOS host: log a WARN
+("operator alert dropped: no SMTP configured at StartOS layer; configure
+in StartOS Settings → Email"), no-op the send, do NOT block the operation
+that triggered the alert. Keysat's primary job is licensing; email is a
+notification side-channel.
+
+**Behavior when SMTP send fails** (auth error, host unreachable): log
+ERROR with the underlying SMTP error, optionally queue for retry with a
+small bounded retry budget (3 attempts, exponential backoff). Don't
+implement a full mailqueue for v1 — failed alerts that retry too many
+times silently drop, the daemon log is the source of truth. Add a real
+mailqueue when an operator reports lost alerts.
+
+## Operator alerts catalog (always-on, recipient = operator)
+
+Each one is a small `tracing`-style call site that emits an `OperatorAlert`
+event, the `operator_alerts` module routes to email + audit log. Listed by
+priority of "operator would want to know within hours."
+
+### Tier 1 — operator action required, send immediately
+
+- `payment_provider.auth_failed` — Zaprite or BTCPay API call returns 401
+  on N consecutive attempts. Means the API key was rotated / revoked.
+  Body includes which provider, when last-good was, suggested fix
+  ("re-run Connect <provider>").
+- `subscriptions.auto_charge_consecutively_failing` — N (default 3)
+  consecutive renewals failed across the active subscription pool, OR
+  M% (default 25%) of recent renewals failed. Pattern detector, not
+  per-sub. Body includes sample failure reasons.
+- `webhook_endpoint.failing` — a single configured webhook endpoint has
+  hit dead-letter status (failed `MAX_ATTEMPTS` deliveries). Body includes
+  the endpoint URL, recent error responses, suggested fix.
+- `master_license.expiring_soon` — master Keysat license expires in N
+  days (default 14). Body includes the upgrade URL.
+- `master_license.expired` — master Keysat license has expired. Body
+  flags which features are now locked (per tier-cap matrix), upgrade URL.
+
+### Tier 2 — operator should know within a day
+
+- `disk_space.low` — Keysat-specific (DB growth). StartOS likely also
+  alerts on overall disk, but Keysat can warn earlier if the DB grows
+  unexpectedly. Skip until operator-reported.
+- `db.backup_overdue` — if Keysat tracks last-backup timestamps. Defer.
+- `update_available` — new Keysat version published to registry, opt-in.
+  Useful but not v1.
+
+### Tier 3 — informational digest
+
+- `weekly_summary` — N licenses issued, N revoked, N renewals settled,
+  $X gross revenue this week. Optional, opt-in. Defer.
+
+**Throttling.** Each alert has a per-alert-kind cooldown (default 6 hours)
+so a flapping provider doesn't email the operator every minute. Cooldown
+state persists in a `operator_alert_throttle (kind, last_sent_at)` table.
+
+## Buyer transactional emails (opt-in per merchant profile)
+
+When `merchant_profiles.keysat_sends_buyer_emails = 1` for the profile
+the event's product belongs to, ALSO send a buyer email (in addition to
+dispatching the webhook). Default `0` everywhere except the master
+Keysat profile, which defaults to `1` because that's where Keysat IS
+the brand. Flipping the flag to `1` on a non-default profile is
+tier-gated to Pro/Patron (Creator-tier operators only have one profile,
+so the question only matters for them in the master-keysat case; the
+gate exists for symmetry with the merchant-profile count cap).
+
+### Event-to-email mapping
+
+| Webhook event | Buyer email |
+|---|---|
+| `license.issued` (one-shot purchase OR first-cycle recurring settle) | **Purchase confirmation + license key delivery** — receipt, the actual key, download/install instructions link. Critical for buyers who closed the tab before saving the key. |
+| `subscription.renewal_pending` | **Renewal reminder** — your next charge is X on Y, link to update card / cancel, link to current subscription state. |
+| `subscription.auto_charge_initiated` | (Optional, off by default) **Auto-charge receipt** — "we charged $X to your saved card, here's the receipt." Some operators want this; most don't (transaction email fatigue). |
+| `subscription.auto_charge_failed` | **Payment failed — action needed** — your card declined, here's the manual-pay link, your subscription is in a grace period until Y. Most-important buyer email since it's the only path to recover the cycle. |
+| `subscription.renewed` | **Renewal receipt** (after settle confirmed). Same content as auto-charge initiated but only sent after confirmation. Pick ONE of this or auto-charge-initiated to avoid double-emails — default to this one. |
+| `subscription.lapsed` | **Subscription ended** — grace period expired, license no longer active, link to re-subscribe. |
+| `code.redeemed` | (Optional, off by default) Discount-code-tied notification, mostly internal. |
+
+### Template system
+
+- One default template per event type, shipped with the binary in
+  `src/notifications/templates/<event>.txt` (markdown source rendered to
+  HTML + plain-text alternatives).
+- Per-merchant-profile branding overrides already exist on the
+  `merchant_profiles` table from the multi-provider plan (`sender_name`,
+  `reply_to`, `support_url`, `brand_color`, `support_email`, plus the
+  optional SMTP-override block). This plan adds the templating-specific
+  fields (`intro_paragraph_md`, `footer_md`, `include_license_key`,
+  `disabled_events`) as additional columns on `merchant_profiles`.
+- Default `sender_name` = profile's `name`. Default `reply_to` =
+  profile's `support_email` (or operator-level fallback if NULL).
+  Default `support_url` = profile's `support_url`. So even with zero
+  customization, emails come from "Recaps <support@recaps.cc>" not
+  "Keysat <noreply@keysat>" — the profile's identity is the source of
+  truth.
+- Templates use a small {{handlebars-style}} variable system. Variables
+  available: `buyer_email`, `license_id` (last 8 chars for display),
+  `policy_slug`, `product_name`, `merchant_profile_name`, `listed_price`
+  + `currency`, `next_renewal_at`, custom fields from the event
+  payload.
+- License-key-delivery template is special: includes the FULL license
+  key (verifiable offline against the operator's pubkey). Operators
+  selling high-value products may want to disable this (deliver
+  out-of-band). Controlled by `merchant_profiles.include_license_key`
+  (default 1).
+
+### Anti-double-email guard
+
+When BOTH a webhook AND a buyer-email fire for the same event, the
+operator's webhook receiver might ALSO be sending its own email — double
+inbox spam for the buyer. Mitigations:
+
+- Admin UI surfaces a clear warning when the operator enables both
+  `keysat_sends_buyer_emails` AND has an active webhook endpoint
+  subscribed to overlapping events: "Recaps's webhook receiver is also
+  subscribed to subscription.renewal_pending. If it's already sending
+  emails, enabling Keysat-direct emails will duplicate buyer mail."
+- Don't try to programmatically prevent — that's brittle and Keysat
+  can't know what the operator's webhook code does. Warn + let them
+  decide.
+
+## Schema changes
+
+New migration `0021_email_notifications.sql` (ships AFTER
+`0020_merchant_profiles.sql` from the multi-provider plan):
+
+```sql
+PRAGMA foreign_keys = ON;
+
+-- Operator's email (the human running the box). Used for operator
+-- alerts. Auto-populated from StartOS account on first boot when
+-- available; editable in admin UI Settings page.
+INSERT OR IGNORE INTO settings(key, value)
+    VALUES ('operator_email', NULL);
+
+-- Per-merchant-profile email flags + customization. Most identity-
+-- and-branding fields (sender_name, reply_to, support_url, brand_color,
+-- support_email, optional SMTP override block) are already on
+-- merchant_profiles from migration 0020. This migration adds the
+-- email-specific behavior columns.
+ALTER TABLE merchant_profiles
+    ADD COLUMN keysat_sends_buyer_emails INTEGER NOT NULL DEFAULT 0
+    CHECK (keysat_sends_buyer_emails IN (0, 1));
+ALTER TABLE merchant_profiles
+    ADD COLUMN intro_paragraph_md TEXT;          -- prepended to every email body
+ALTER TABLE merchant_profiles
+    ADD COLUMN footer_md TEXT;                   -- replaces default footer
+ALTER TABLE merchant_profiles
+    ADD COLUMN include_license_key INTEGER NOT NULL DEFAULT 1
+    CHECK (include_license_key IN (0, 1));
+ALTER TABLE merchant_profiles
+    ADD COLUMN disabled_events TEXT;             -- JSON array of event_type strings
+
+-- On the master Keysat instance, flip the default profile's flag to ON
+-- (it's the one place buyers are buying Keysat-the-product and the
+-- email comes from Keysat). On every other operator's instance, the
+-- default profile starts with the flag OFF — they keep using their own
+-- email pipeline via webhooks. Operators can flip it ON later
+-- (tier-gated for non-default profiles).
+--
+-- This UPDATE is conditional: only flip if the operator_name resolves
+-- to "Keysat" (i.e., this is the master instance). Other operators
+-- will see their default profile stay at 0.
+UPDATE merchant_profiles
+   SET keysat_sends_buyer_emails = 1
+ WHERE is_default = 1
+   AND name = 'Keysat';
+
+-- Throttle state for operator alerts (one cooldown per alert kind).
+CREATE TABLE operator_alert_throttle (
+    kind            TEXT PRIMARY KEY,
+    last_sent_at    TEXT NOT NULL,
+    last_payload    TEXT             -- JSON, last alert body for dedup
+);
+
+-- Audit trail of emails sent. Operator-debuggable; bounded by a TTL
+-- sweep so it doesn't grow forever.
+CREATE TABLE email_log (
+    id                  TEXT PRIMARY KEY,
+    sent_at             TEXT NOT NULL,
+    to_address          TEXT NOT NULL,
+    subject             TEXT NOT NULL,
+    audience            TEXT NOT NULL,   -- 'operator' | 'buyer'
+    merchant_profile_id TEXT,            -- which profile's branding/SMTP was used; NULL for operator alerts
+    event_type          TEXT,            -- nullable; some operator alerts not event-driven
+    product_id          TEXT,            -- nullable for operator alerts
+    invoice_id          TEXT,            -- nullable
+    subscription_id     TEXT,            -- nullable
+    license_id          TEXT,            -- nullable
+    status              TEXT NOT NULL,   -- 'sent' | 'failed' | 'dropped_no_smtp'
+    error_message       TEXT,
+    CHECK (audience IN ('operator', 'buyer')),
+    CHECK (status IN ('sent', 'failed', 'dropped_no_smtp'))
+);
+CREATE INDEX idx_email_log_sent_at ON email_log(sent_at);
+CREATE INDEX idx_email_log_audience ON email_log(audience);
+```
+
+## Rust code changes
+
+- New `src/notifications/mod.rs`:
+  - `pub struct NotificationsService { default_smtp: SmtpConfig, db: SqlitePool }`
+  - `pub async fn send_email(&self, profile: Option<&MerchantProfile>, to: &str, subject: &str, body_text: &str, body_html: Option<&str>) -> Result<()>`
+    — when `profile` is `Some`, use the profile's SMTP override fields if present; otherwise fall back to the StartOS-level SMTP. Operator alerts pass `None` (always uses the default SMTP since they don't belong to any business).
+  - Logs to `email_log` table on every attempt regardless of outcome,
+    tagging which profile's config was used.
+  - Implementation: use `lettre` crate (well-maintained Rust SMTP
+    client) with TLS/STARTTLS support.
+- New `src/notifications/templates.rs`:
+  - Template registry mapping event_type → default template.
+  - Render function: takes template + variables + per-profile overrides
+    → returns subject, text body, HTML body.
+  - Templates embedded via `include_str!` so no filesystem dependency
+    in container.
+- New `src/operator_alerts.rs`:
+  - `pub fn alert(state: &AppState, kind: OperatorAlertKind, payload: serde_json::Value)`
+  - Reads throttle state, sends email (via default SMTP, no profile)
+    if cooldown elapsed, persists last_sent_at.
+- New call sites in existing modules:
+  - `subscriptions.rs` — `auto_charge_consecutively_failing` detector
+    (windowed counter)
+  - `payment/zaprite/client.rs` + `payment/btcpay/client.rs` —
+    `payment_provider.auth_failed` on N consecutive 401s
+  - `webhooks.rs` (delivery worker) — `webhook_endpoint.failing` when
+    an endpoint hits dead-letter
+  - `tier.rs` — `master_license.expiring_soon` /
+    `master_license.expired` daily check
+- Extend `webhooks::dispatch` to also call `notifications` when the
+  product's `merchant_profile.keysat_sends_buyer_emails = 1` AND the
+  event is buyer-relevant. The notification call passes the profile,
+  so per-profile SMTP / branding applies.
+- `AppState::config` gains an `smtp: Option<SmtpConfig>` field
+  (default StartOS-level SMTP), populated at startup.
+- `startos/main.ts` (TypeScript wrapper): read StartOS SMTP config and
+  pass it to the daemon as env vars or a generated config file.
+
+## Admin UI changes (in `web/index.html`)
+
+- **Settings page** → new "Notifications" disclosure (operator-level):
+  - Operator email field (auto-populated from StartOS, editable)
+  - Default SMTP status (connected/error/not configured), inherited from
+    StartOS
+  - "Send test email to operator" button to verify the default SMTP path
+  - List of recent emails sent (paginated, from `email_log`), filterable
+    by audience (operator vs buyer) and by merchant profile
+- **Merchant Profile edit page** (already exists from multi-provider
+  plan) → "Buyer emails" disclosure:
+  - Toggle: "Have Keysat send buyer emails for this merchant profile"
+    (default off; default on for the master Keysat profile only)
+  - Per-event opt-outs (checkboxes for each buyer-event row in the
+    Event-to-email mapping above)
+  - "Intro paragraph" + "Footer" markdown fields
+  - "Include license key in confirmation email" checkbox
+  - "Test send" button rendering one of the templates against the
+    profile's SMTP config + branding
+  - Inline warning if any active webhook is subscribed to overlapping
+    events (anti-double-email guard from above)
+- (Branding + SMTP-override fields live on the existing Merchant
+  Profile edit page sections, not duplicated here — they're owned by
+  the multi-provider plan.)
+
+## Sequencing
+
+Single cycle if it's all you ship. Otherwise consider this order:
+
+1. **Phase 1 — StartOS SMTP wiring + notifications module** (`:NN+1`). No
+   call sites yet, just the plumbing + a `Send test email` button on the
+   Settings page so operators can validate the path. Low risk, immediately
+   testable.
+2. **Phase 2 — Operator alerts** (`:NN+2`). Wire in the 4-5 Tier-1 alerts.
+   No buyer-facing changes. Operators get immediate value.
+3. **Phase 3 — Buyer emails infrastructure** (`:NN+3`). Schema +
+   template engine + admin UI for the per-merchant-profile config.
+   Default everything off — no behavior change yet.
+4. **Phase 4 — Buyer email triggers** (`:NN+4`). Wire the webhook-
+   dispatch path to also send emails when configured. Default ON for the
+   master Keysat profile, OFF everywhere else. This is the user-visible
+   cut.
+
+Phases can be one release each (4 routine bumps) or rolled together if
+they're shipped as a coherent feature.
+
+## Verification
+
+1. **Test send from Settings page** — verifies StartOS SMTP integration
+   end-to-end without needing a real event to trigger.
+2. **Operator alert test**: revoke the Zaprite API key on Zaprite's
+   dashboard, trigger any purchase attempt → expect a Tier-1 email within
+   the throttle window naming the provider and suggesting the fix.
+3. **Buyer email test (master Keysat)**: buy a Keysat self-license on
+   the master keysat.xyz instance (its profile has the flag = 1 from
+   the migration) → expect a Keysat-branded confirmation email with the
+   license key, sent from the Keysat profile's SMTP config + branding.
+4. **Buyer email test (Recaps operator path)**: on an operator instance
+   with a Recaps merchant profile (flag = 0), buy a Recaps license →
+   confirm Keysat sends NO buyer email; only the webhook fires for
+   Recaps's receiver to handle.
+5. **Per-profile SMTP test (Pro/Patron)**: on a Pro-tier operator
+   instance, create two profiles, each with its own SMTP override
+   (different sender domains). Buy a product on each. Confirm each
+   buyer email arrives from the correct sender domain with the correct
+   profile branding (verifies the per-profile SMTP routing).
+6. **Anti-double-email warning**: enable
+   `merchant_profiles.keysat_sends_buyer_emails` on a profile that has
+   a webhook subscribed to overlapping events → confirm the admin UI
+   shows the warning.
+7. **Throttle test**: trigger the same operator alert twice in quick
+   succession → confirm only one email sent, second one suppressed,
+   audit log shows the cooldown.
+
+## Out of scope for this work — future considerations
+
+- **Other notification channels** (Slack, Discord, push). Email is the
+  highest-leverage channel and matches StartOS's existing infrastructure.
+  Other channels are a natural extension if any operator asks.
+- **Operator-side email-domain authentication setup** (DKIM/SPF
+  configuration help). Keysat consumes whatever StartOS gives it;
+  operators handle their own deliverability hygiene. We can link to a
+  docs page from the Settings UI.
+- **HTML email template editor** in the admin UI. Operators get
+  markdown + a small variable set; if they want full template control,
+  they use webhooks + their own pipeline. Adding a WYSIWYG editor is
+  a much bigger UI investment.
+- **Per-customer email preferences** (let buyers opt out of renewal
+  reminders). Not a v1 feature — buyers can ignore emails. Build when
+  someone hits GDPR / CAN-SPAM compliance edge cases at scale.
+- **Multi-language email templates**. Defer; templates ship English-only.
+- **Transactional email service integrations** (SendGrid/Postmark/etc.
+  in addition to or instead of StartOS SMTP). StartOS SMTP is the
+  right default — it's already configured and the operator pays nothing
+  extra. Other providers are a deferred option.
+
+## How this composes with the multi-provider / merchant-profile plan
+
+The merchant-profile plan ships first (`migration 0020`) and creates the
+`merchant_profiles` table along with the identity, branding, and
+optional-SMTP-override fields. This plan layers on top (`migration
+0021`) adding the email-behavior columns (`keysat_sends_buyer_emails`,
+`intro_paragraph_md`, `footer_md`, `include_license_key`,
+`disabled_events`) plus the operator-level `operator_email` setting, the
+`operator_alert_throttle` table, and the `email_log` table.
+
+Admin UI work is symmetric: the multi-provider plan owns the Merchant
+Profile edit page's identity, branding, and providers sections. This
+plan adds a "Buyer emails" disclosure on the same page.
+
+No code conflict — the merchant-profile plan touches payment routing,
+this plan touches the dispatch tail. They compose cleanly. Shipping
+them in sequence (rather than as one combined cut) keeps each cycle's
+scope reviewable.

multi-provider-payment-model.md

@@ -0,0 +1,585 @@
+# Keysat multi-merchant-profile + multi-provider model
+
+## Context
+
+Today both `btcpay_config` and `zaprite_config` are singleton rows
+(`id INTEGER PRIMARY KEY CHECK (id = 1)`), and `SETTING_ACTIVE_PROVIDER`
+picks one of the two as the daemon's process-wide active provider. Every
+call to `state.payment_provider()` returns that one provider, regardless of
+which product is being sold. There's no concept of a "merchant" or "seller"
+identity anywhere — every product on a Keysat instance is implicitly being
+sold by the same legal entity, through the same payment account, with the
+same branding and the same post-purchase landing page.
+
+That model breaks the moment a software author wants to run ONE Keysat
+instance for multiple distinct businesses. Concrete example: one operator
+sells **Recaps** licenses (settled to a Recaps Zaprite org, branded as
+Recaps, buyers redirected to `recaps.cc`) AND **Keysat** licenses (settled
+to a Keysat Zaprite org, branded as Keysat, buyers redirected to
+`keysat.xyz`). Today's architecture forces both to share one merchant
+identity, one provider account, one branding set, one redirect URL.
+
+This plan introduces a **merchant profile** layer that owns business
+identity, branding, redirect, optional SMTP, AND a set of payment
+providers. Products attach to a merchant profile (not directly to a
+provider). The buyer sees the merchant profile's brand at checkout and
+picks a payment rail from the providers attached to that profile.
+
+Tier-gating: Creator (free) gets 1 merchant profile. Pro/Patron get N.
+
+## Why this shape, not the simpler "per-product provider override"
+
+An earlier draft of this plan had products carry a nullable
+`payment_provider_id` override directly. That worked but conflated two
+concerns: **business identity** (who's selling this? what's the brand?
+where do buyers land?) and **payment routing** (which Stripe / Bitcoin
+account receives the money?). In practice an operator running two
+businesses wants every product of business A to share a brand AND a set of
+payment accounts AND a redirect; copying those fields onto every product
+of that business would be redundant and error-prone.
+
+Merchant profile cleanly separates the two:
+- **Profile** = the business identity (brand, redirect, support contact,
+  optional SMTP), and the set of payment providers that legally settle TO
+  that business.
+- **Provider** = the technical credential to a specific payment account
+  (BTCPay store + API key, OR Zaprite org + API key). One provider per
+  account; a profile can have many providers (e.g. BTCPay for Bitcoin
+  AND Zaprite for card).
+- **Product** = what's being sold, attached to one profile.
+
+This also makes **buyer-currency routing** (previously a deferred future-
+consideration) fall out for free: the buy page shows which payment rails
+the product's profile supports, the buyer picks Bitcoin / Lightning /
+Card, we route through the right provider.
+
+## Design overview
+
+### Data model
+
+```
+merchant_profiles (1) ──────< (N) payment_providers
+                  (1) ──────< (N) products
+                  (1) ──────< (N) subscriptions  [snapshot on create]
+```
+
+- Exactly one `merchant_profiles.is_default = 1` row. Auto-created on
+  first boot after upgrade, populated from existing
+  `SETTING_OPERATOR_NAME`. New operators get one default profile too.
+- Each `payment_provider` belongs to exactly ONE profile
+  (`merchant_profile_id NOT NULL`). Providers move with the business.
+- Each product has `merchant_profile_id NOT NULL`. Default to the
+  default profile.
+- Each subscription snapshots BOTH `merchant_profile_id` and
+  `payment_provider_id` at creation, so mid-cycle changes to the product
+  don't silently redirect existing subs to a different business or rail.
+
+### Buy-page resolution at runtime
+
+1. Buyer hits `/buy/<slug>`.
+2. Server loads product → product's merchant profile → profile's attached
+   providers.
+3. Buy page renders the merchant profile's brand (name, color, support
+   link), the product's price/tiers, and a payment-method picker exposing
+   every rail the attached providers offer (Lightning, on-chain, card,
+   etc.).
+4. Buyer picks a rail. The picker resolves to one provider (e.g., "Card"
+   → the Zaprite provider attached to this profile).
+5. Server calls `state.payment_provider_for(profile_id, rail)` →
+   `create_invoice` on that provider.
+6. After settle, redirect goes to profile's
+   `post_purchase_redirect_url` if set, else Keysat's default
+   `/thank-you?invoice_id=…` page.
+
+### Subscription renewal resolution
+
+Renewal worker reads `sub.payment_provider_id` and
+`sub.merchant_profile_id` from the subscription snapshot — never re-
+resolves from the product. This protects existing buyers from operator
+edits.
+
+## Tier gating
+
+- **Creator (free)** — exactly 1 merchant profile. Auto-created on first
+  boot; can be edited but not deleted, and the create-profile endpoint
+  refuses with 402 + upgrade URL if a Creator already has one.
+- **Pro / Patron** — unlimited merchant profiles. Same cap-resolution
+  pattern as the existing `unlimited_products` / `unlimited_policies`
+  entitlements (`tier::current()` returns the cap; admin endpoint checks
+  before insert; the existing tier-cap modal shows the upgrade CTA).
+
+New entitlement string: `unlimited_merchant_profiles`. Master Keysat's
+Pro and Patron policies need this added to their entitlement lists; the
+master operator's self-license then signs with it baked in.
+
+## Schema (migration 0020)
+
+```sql
+PRAGMA foreign_keys = ON;
+
+CREATE TABLE merchant_profiles (
+    id                          TEXT PRIMARY KEY,           -- UUID v4
+    name                        TEXT NOT NULL,              -- "Recaps", "Keysat"
+    legal_name                  TEXT,                       -- optional, for receipts/tax
+    support_url                 TEXT,
+    support_email               TEXT,
+    brand_color                 TEXT,                       -- hex
+    post_purchase_redirect_url  TEXT,                       -- NULL = Keysat default /thank-you
+    is_default                  INTEGER NOT NULL DEFAULT 0,
+    -- Optional per-profile SMTP override. NULL means inherit the
+    -- StartOS-level / Keysat-singleton SMTP config. Lets a Pro/Patron
+    -- operator running 3 businesses send emails from 3 different
+    -- domains/senders WITHOUT having to configure 3 separate StartOS
+    -- accounts. Pairs with the keysat-smtp-emails plan.
+    smtp_host                   TEXT,
+    smtp_port                   INTEGER,
+    smtp_username               TEXT,
+    smtp_password               TEXT,                       -- encrypted at rest (TBD)
+    smtp_from_address           TEXT,
+    smtp_from_name              TEXT,
+    smtp_use_starttls           INTEGER NOT NULL DEFAULT 1,
+    created_at                  TEXT NOT NULL,
+    updated_at                  TEXT NOT NULL,
+    CHECK (is_default IN (0, 1)),
+    CHECK (smtp_use_starttls IN (0, 1))
+);
+CREATE UNIQUE INDEX idx_merchant_profiles_one_default
+    ON merchant_profiles(is_default) WHERE is_default = 1;
+
+CREATE TABLE payment_providers (
+    id                  TEXT PRIMARY KEY,                   -- UUID v4
+    merchant_profile_id TEXT NOT NULL REFERENCES merchant_profiles(id),
+    kind                TEXT NOT NULL,                      -- 'btcpay' | 'zaprite'
+    label               TEXT NOT NULL,                      -- "Recaps BTCPay", operator-set
+    api_key             TEXT NOT NULL,
+    base_url            TEXT NOT NULL,
+    webhook_id          TEXT,
+    webhook_secret      TEXT,                               -- BTCPay HMAC; NULL for Zaprite
+    store_id            TEXT,                               -- BTCPay only
+    connected_at        TEXT NOT NULL,
+    updated_at          TEXT NOT NULL,
+    CHECK (kind IN ('btcpay', 'zaprite'))
+);
+CREATE INDEX idx_payment_providers_profile ON payment_providers(merchant_profile_id);
+-- Within a profile, at most one provider of each kind (avoid the
+-- two-BTCPay-providers-same-business confusion):
+CREATE UNIQUE INDEX idx_payment_providers_profile_kind
+    ON payment_providers(merchant_profile_id, kind);
+
+ALTER TABLE products
+    ADD COLUMN merchant_profile_id TEXT
+    REFERENCES merchant_profiles(id);
+CREATE INDEX idx_products_profile ON products(merchant_profile_id);
+
+ALTER TABLE subscriptions
+    ADD COLUMN merchant_profile_id TEXT REFERENCES merchant_profiles(id),
+    ADD COLUMN payment_provider_id TEXT REFERENCES payment_providers(id);
+CREATE INDEX idx_subs_profile  ON subscriptions(merchant_profile_id);
+CREATE INDEX idx_subs_provider ON subscriptions(payment_provider_id);
+```
+
+### Migration body (data port)
+
+```sql
+-- 1. Create the default merchant profile from existing operator settings.
+INSERT INTO merchant_profiles(
+    id, name, support_url, support_email, brand_color,
+    post_purchase_redirect_url, is_default, created_at, updated_at
+)
+SELECT lower(hex(randomblob(16))),
+       COALESCE((SELECT value FROM settings WHERE key='operator_name'), 'Keysat'),
+       NULL, NULL, NULL, NULL,
+       1, datetime('now'), datetime('now');
+
+-- 2. Migrate btcpay_config → payment_providers (if present), attached to default.
+INSERT INTO payment_providers(
+    id, merchant_profile_id, kind, label,
+    api_key, base_url, webhook_id, webhook_secret, store_id,
+    connected_at, updated_at
+)
+SELECT lower(hex(randomblob(16))),
+       (SELECT id FROM merchant_profiles WHERE is_default = 1),
+       'btcpay', 'BTCPay (migrated)',
+       api_key, base_url, webhook_id, webhook_secret, store_id,
+       connected_at, connected_at
+FROM btcpay_config;
+
+-- 3. Same for zaprite_config.
+INSERT INTO payment_providers(
+    id, merchant_profile_id, kind, label,
+    api_key, base_url, webhook_id, webhook_secret, store_id,
+    connected_at, updated_at
+)
+SELECT lower(hex(randomblob(16))),
+       (SELECT id FROM merchant_profiles WHERE is_default = 1),
+       'zaprite', 'Zaprite (migrated)',
+       api_key, base_url, webhook_id, NULL, NULL,
+       connected_at, connected_at
+FROM zaprite_config;
+
+-- 4. Drop the old singleton tables.
+DROP TABLE btcpay_config;
+DROP TABLE zaprite_config;
+DELETE FROM settings WHERE key = 'active_payment_provider';
+
+-- 5. Backfill products + subscriptions to point at the migrated default.
+UPDATE products
+   SET merchant_profile_id = (SELECT id FROM merchant_profiles WHERE is_default = 1);
+UPDATE subscriptions
+   SET merchant_profile_id = (SELECT id FROM merchant_profiles WHERE is_default = 1),
+       payment_provider_id = (
+           SELECT id FROM payment_providers
+           WHERE merchant_profile_id = (SELECT id FROM merchant_profiles WHERE is_default = 1)
+             AND kind = (
+                 -- Resolve the original provider for back-compat. Use whichever
+                 -- provider the active-provider setting pointed at; fall back to
+                 -- BTCPay if both exist (preserves existing single-provider
+                 -- operator behavior).
+                 CASE
+                     WHEN EXISTS (SELECT 1 FROM payment_providers
+                                  WHERE merchant_profile_id =
+                                        (SELECT id FROM merchant_profiles WHERE is_default = 1)
+                                    AND kind = 'btcpay')
+                     THEN 'btcpay'
+                     ELSE 'zaprite'
+                 END
+             )
+       );
+```
+
+Additive-then-cutover; not reversible without a backup restore. Release
+notes call this out as a one-way migration (consistent with the v0.2.0:1+
+migration framing). Existing single-provider operators see no behavior
+change — their setup becomes "1 profile + 1 provider," products and subs
+all attach to that profile.
+
+## Rust changes
+
+**`src/merchant_profiles.rs`** (new):
+- `pub struct MerchantProfile` mirroring a row.
+- `pub async fn list(pool) -> Vec<MerchantProfile>`,
+  `get_by_id`, `get_default`, `create`, `update`, `delete`.
+- Tier gate inside `create` — refuses with `AppError::TierCap` (existing
+  type that triggers the 402 + upgrade modal) when Creator already has
+  one profile.
+
+**`src/payment/mod.rs`**:
+- `pub struct PaymentProviderConfig` mirroring a row (now includes
+  `merchant_profile_id`).
+- `pub fn build_provider(cfg: &PaymentProviderConfig) -> Arc<dyn PaymentProvider>`
+  factory dispatching on `kind`.
+- `repo::list_providers_for_profile(pool, profile_id)`,
+  `repo::get_provider_by_id`, etc.
+- Drop `SETTING_ACTIVE_PROVIDER` constant + `read/write_active_provider_preference`.
+- Add a "rail" concept: each provider impl declares which payment rails
+  it offers (`enum Rail { Lightning, OnChain, Card, … }`). The buy page
+  uses this to render the payment-method picker.
+
+**`src/api/mod.rs` (AppState)**:
+- Replace single `payment_provider` accessor with two:
+  - `state.merchant_profile_for(product_id) -> MerchantProfile`
+  - `state.payment_provider_by_id(provider_id) -> Arc<dyn PaymentProvider>`
+- Add a cache `provider_cache: Cache<String, Arc<dyn PaymentProvider>>`
+  keyed by provider id; invalidated on connect/disconnect/edit.
+
+**Call sites that switch**:
+- `src/api/purchase.rs` — resolve product → profile, then accept a
+  rail selection from the request body (or default to "first rail" if
+  product has no override), then build the provider; pass
+  `merchant_profile_id` AND `payment_provider_id` to subscription create.
+- `src/api/upgrade.rs` — derive from license → product → profile; pick
+  the same rail the original sub used (snapshot).
+- `src/subscriptions.rs` — use `sub.payment_provider_id` snapshot
+  (already planned in the prior multi-provider draft); additionally
+  use `sub.merchant_profile_id` to load redirect URL / branding for
+  the renewal webhook payload.
+- `src/tipping.rs`, `src/reconcile.rs` — same pattern.
+
+**`src/api/webhook.rs`** — router unchanged from the prior multi-provider
+draft: `/v1/{kind}/webhook/{provider_id}` is still the path. The
+`provider_id` resolves to a profile transitively, and the webhook
+handler doesn't need to know about profiles (it just needs to validate
+the payload against the right provider's secret and update the right
+invoice).
+
+**`src/api/btcpay_authorize.rs` and `src/api/zaprite_authorize.rs`** —
+connect flows:
+- Connect now takes a `merchant_profile_id` query param. Default = the
+  default profile if not specified.
+- Refuses if a provider of the same kind already exists on that profile
+  (the unique index would error; we want a clean 409 with a helpful
+  message: "Recaps already has a Zaprite provider — disconnect it first
+  or connect to a different profile").
+- "Disconnect" deletes the provider row; if it was the last provider on
+  the profile AND that profile has active products/subscriptions, the
+  admin UI prompt requires picking a replacement before delete.
+- New endpoint `POST /v1/admin/merchant-profiles/{id}` CRUD endpoints
+  for profile management.
+
+## Subscription snapshot semantics
+
+`subscriptions.merchant_profile_id` AND `subscriptions.payment_provider_id`
+are both set on create and never changed by product edits. If the operator
+later moves a product to a different merchant profile:
+
+- New purchases on that product create subscriptions tied to the NEW
+  profile + provider.
+- Existing subscriptions keep renewing through their ORIGINAL profile +
+  provider.
+- Trade-off: an admin "re-route this subscription" action exists as a
+  manual flow (see "Mid-cycle subscription migration" in future
+  considerations) — never automatic.
+
+## Admin UI changes (in `web/index.html`)
+
+### Settings → Merchant Profiles (new top-level page)
+
+- List view: table of profiles with name, default badge, attached
+  provider kinds (icons for BTCPay / Zaprite), product count, action
+  menu (edit, set default, delete).
+- "Add Merchant Profile" button: tier-gated. On Creator with 1 profile,
+  the button shows the tier-cap upgrade modal instead.
+- Profile edit page: form with all the merchant_profile fields. Section
+  for "Payment providers" listing attached providers with disconnect/
+  reconnect; "Connect BTCPay" and "Connect Zaprite" buttons within the
+  profile (which is how the connect flow's `merchant_profile_id` query
+  param gets populated). Section for optional per-profile SMTP override
+  (collapsed by default; the keysat-smtp-emails plan covers the form
+  fields in detail).
+- Delete profile: refused if the profile has any active products or
+  unsettled subscriptions; otherwise prompts confirm.
+
+### Existing Payment Providers page (rename → drop)
+
+- The current "Payment Providers" section on the Settings page is
+  removed; provider config now lives INSIDE each merchant profile's
+  edit page. There's no top-level "list all providers across all
+  profiles" view — providers are scoped to their profile.
+
+### Product create/edit page
+
+- New "Settle through" picker:
+  - "Merchant profile" dropdown — required, defaults to the default
+    profile. Lists all profiles the operator has configured.
+  - Below it, an info chip showing which payment rails buyers will be
+    offered ("Card via Zaprite + Lightning via BTCPay") based on the
+    chosen profile's attached providers. If the profile has no
+    providers, the operator sees an error: "This merchant profile has
+    no payment providers connected — buyers can't pay until you add
+    one."
+
+### Buy page (`/buy/<slug>`)
+
+- Brand block at top renders the merchant profile's `name`, optionally
+  with `brand_color` accent, and "Sold by {name}" subtitle.
+- Existing tier-card UI unchanged except for the payment-method picker:
+  if the profile has 2+ providers, render a "Pay with" picker (Card /
+  Lightning / Bitcoin) before the final Pay button. If only 1 provider,
+  hide the picker (current behavior).
+- After payment, redirect respects profile's
+  `post_purchase_redirect_url` if set; falls back to Keysat's default
+  thank-you page.
+
+## Files modified (estimated)
+
+- `migrations/0020_merchant_profiles.sql` (new)
+- `src/merchant_profiles.rs` (new)
+- `src/payment/mod.rs` — provider factory + rail concept + profile-aware
+  accessors
+- `src/payment/btcpay.rs`, `src/payment/zaprite/{client,config,provider}.rs`
+  — constructors take row config; declare rails
+- `src/api/{purchase,upgrade,webhook,btcpay_authorize,zaprite_authorize,
+  merchant_profiles}.rs` — call sites + new CRUD endpoints
+- `src/api/mod.rs` (AppState) — provider cache + profile accessors
+- `src/db/repo.rs` — profile + provider repo helpers
+- `src/subscriptions.rs` — snapshot profile_id + provider_id
+- `src/tier.rs` — wire `unlimited_merchant_profiles` entitlement
+- `src/tipping.rs`, `src/reconcile.rs` — pass profile context
+- `web/index.html` — new Merchant Profiles section + product picker +
+  buy-page profile branding + payment-method picker
+- `startos/versions/v0.2.0.ts` — bump (TBD which `:NN`), release notes
+  flagging one-way migration + Creator tier cap
+
+## Verification
+
+1. **Unit/integration tests**: profile CRUD with tier gating
+   (Creator hits cap, Pro/Patron doesn't); subscription snapshot
+   stickiness across product moves; provider-by-rail resolution.
+2. **Migration test**: copy a production-shape DB (BTCPay singleton +
+   one product + one active sub + active_provider setting), run
+   migrations, confirm: one default profile exists named per operator,
+   one BTCPay provider attached, product points to default profile,
+   sub points to both default profile + the migrated BTCPay provider.
+3. **Sandbox end-to-end**:
+   - On a Pro-tier instance, create two profiles: "Recaps" and "Keysat".
+   - Connect a Zaprite sandbox org to Recaps; connect a different
+     Zaprite sandbox org to Keysat.
+   - Create a Recaps product, attach to Recaps profile. Create a Keysat
+     product, attach to Keysat profile.
+   - Buy each. Confirm:
+     - Recaps purchase shows "Sold by Recaps" branding on buy page,
+       redirects to Recaps's `post_purchase_redirect_url`, settles to
+       the Recaps Zaprite dashboard, webhook hits
+       `/v1/zaprite/webhook/{recaps-provider-id}`.
+     - Keysat purchase shows Keysat branding, redirects to Keysat
+       thank-you, settles to Keysat Zaprite dashboard.
+4. **Multi-rail per profile**:
+   - On the Recaps profile, also connect BTCPay (separate provider).
+   - Buy the Recaps product again. Buy page now shows "Pay with Card"
+     and "Pay with Lightning" picker.
+   - Pick card → Zaprite. Pick Lightning → BTCPay. Confirm each settles
+     to the correct dashboard.
+5. **Creator tier cap**:
+   - On a Creator-tier instance, attempt to create a second profile.
+   - Expect 402 + upgrade modal pointing at the master Keysat upgrade
+     URL.
+6. **Backward-compat smoke**:
+   - Existing operator upgrades from `:45` to this version. Confirm
+     they see one profile auto-created with their existing operator
+     name + connected providers attached + all products + subs
+     linked through.
+   - Webhook delivered to OLD `/v1/zaprite/webhook` URL (no provider
+     id) still settles via the migrated default provider.
+
+## Sequencing
+
+This is a bigger change than the original multi-provider draft. Feasible
+in one cycle but the admin UI surface is meaningful. Two reasonable
+options:
+
+**Option A — single cut.** All schema + Rust + admin UI in one release.
+Cleaner UX (no half-shipped intermediate states) but a heavier cut.
+Estimate: 2–3 focused days.
+
+**Option B — two cuts.**
+- Cut 1: Schema migration + Rust resolution layer + buy-page resolution.
+  Admin UI stays mostly unchanged (one auto-created profile, existing
+  payment providers page shows the default profile's providers).
+  Lower risk; existing operators see no UX change.
+- Cut 2: Full admin UI surface (Merchant Profiles top-level page,
+  per-profile connect flows, profile picker on product page). Layered
+  on after Cut 1 is stable.
+
+I'd lean toward **B** — the data-model and resolution-layer changes
+deserve their own focused cycle, and the UI work benefits from real
+operator feedback on the new shape before we commit to the admin UX.
+
+## Future considerations — still on the roadmap
+
+The merchant-profile shape makes most of these straight extensions.
+Listed roughly in order of "smallest leap from this foundation."
+
+### 1. Buyer-currency routing — natively supported
+
+**What this plan already does.** A profile with multiple providers
+already exposes a multi-rail picker on the buy page. Currency
+routing is the same shape: buyer picks USD → routes through the
+profile's card-capable provider (Zaprite); picks BTC → routes through
+Bitcoin-capable (BTCPay). No follow-up work needed beyond the
+multi-rail picker.
+
+**What's left for a polish pass.** Currency-aware tier card pricing
+(if a product is listed in USD but the buyer picks BTC, show the
+sat-equivalent live). Already partly there with the multi-currency
+work in v0.1.0:43+; the remaining piece is the buy-page rate
+display.
+
+### 2. Per-policy provider — "free tier no payment, paid tiers via Stripe"
+
+**Value.** A product with `Free`, `Pro $5/mo` and `Patron 50000
+sats/mo` policies could route the paid policies through different
+providers. Free tier has no provider at all (today it falls through
+to whichever is configured + a $0 invoice).
+
+**What changes from this plan's foundation.** Add a nullable
+`payment_provider_id` to `policies` (a SECOND override). Resolution
+order: policy override → product's profile → buyer's rail pick.
+
+**Complexity.** Mostly UI (the policy edit modal gets a "settle
+through" picker). Half a day on top of this foundation. Probably
+not needed for v1 — the per-profile-multi-provider model handles
+most cases.
+
+### 3. Mid-cycle subscription migration — "move my subs to a new merchant"
+
+**Value.** Operator changes payment processors (e.g., switches a
+profile's Zaprite org) and wants existing recurring subs to
+re-attach to the new provider/profile.
+
+**What changes from this plan's foundation.** New admin endpoint
+`POST /v1/admin/subscriptions/{id}/migrate` that updates the sub's
+`merchant_profile_id` and/or `payment_provider_id`, drops the
+captured `zaprite_payment_profile_id` (which is scoped to the old
+org), and either prompts the buyer to re-save their card OR issues a
+one-time invoice on the new provider to capture a fresh profile on
+settle.
+
+**Complexity.** The data model is trivial — the hard part is the
+buyer-communication step. Recommended to defer until a real
+operator asks. Half a day for endpoint + UI.
+
+### 4. Auto-failover within a merchant profile
+
+**Value.** A profile has BTCPay primary + Zaprite warm-standby. If
+BTCPay's webhook deliveries start failing or its API is
+unreachable, Keysat automatically routes the next purchase through
+Zaprite without manual intervention.
+
+**What changes.** New `payment_providers.fallback_provider_id`
+(nullable FK to another provider on the SAME profile). Purchase
+flow tries the primary; on `create_invoice` failure (network, 5xx,
+timeout), retries with the fallback. Health-check loop also pings
+each provider periodically and records last-known-good status for
+admin UI.
+
+**Complexity.** Genuine — failure detection is the hard part. 1–2
+days for the naive version, more for proper circuit-breaker logic.
+Lower priority because most operators tolerate manual intervention
+for brief outages.
+
+### 5. Multi-tenant Keysat boxes — "Keysat as a service"
+
+**Value.** Separate business shape: a SaaS provider runs ONE box
+that hosts licensing for many INDEPENDENT operators (each with
+their own merchant profiles, products, customers, branding, auth).
+Different product than the operator-owned licensing server Keysat
+is today.
+
+**What changes.** Almost everything — every table needs a
+`tenant_id` (or `operator_id`), auth becomes per-tenant, the admin
+UI becomes a tenant-scoped view, etc.
+
+**Recommendation.** Don't plan against this. If the SaaS shape ever
+becomes interesting, it's a fork or v2.0 product, not a layered-on
+feature. The merchant-profile schema we're building IS however a
+useful foundation IF that pivot happens, because per-tenant
+billing already maps to per-tenant set-of-merchant-profiles.
+
+---
+
+The merchant-profile foundation we're shipping in this cycle is
+deliberately shaped to make 1–3 above straight extensions. 4 is a
+different kind of work (failure detection, not data model). 5 is a
+different product.
+
+## How this composes with the SMTP / operator-alerts plan
+
+See `/Users/macpro/.claude/plans/keysat-smtp-emails.md` (companion
+plan).
+
+- Per-profile SMTP override fields (in this migration) replace what
+  the SMTP plan originally placed on `products`. Email branding is
+  business-level, not product-level, so it belongs on
+  `merchant_profiles`.
+- The SMTP plan's "buyer transactional emails" opt-in becomes a
+  per-profile flag (`merchant_profiles.keysat_sends_buyer_emails`)
+  rather than per-product. Master Keysat's profile defaults it to
+  on; Recaps profile defaults it off (Recaps handles its own buyer
+  emails via webhooks).
+- The SMTP plan's operator alerts are unchanged — those go to the
+  operator personally (StartOS-level email), independent of
+  merchant profiles.
+
+Migration order: ship this plan first (merchant_profiles table
+exists), then the SMTP plan layers per-profile SMTP + email
+settings on top of the new table.