Save in-progress keysat integration and StartOS 0.4 work

Snapshot of the working tree before cleanup. Captures:
- Keysat licensing: server/license.js, /api/license/* endpoints in
  server/index.js, activation modal in public/index.html, embedded
  Ed25519 issuer key (assets/issuer.pub).
- StartOS 0.4 expansion: setApiKey action, version files v0.1.1
  through v0.1.15, file-models/config.json.ts, manifest updates.
- Self-hosted registry server (startos-registry/).
- Build/deploy scripts (bin/bump-version.sh, bin/deploy.sh, vendored
  yt-dlp binary), .gitignore, .deploy.env.example.
- Recent design docs (KEYSAT_INTEGRATION.md, UPGRADE-DESIGN.md) —
  retained here so they remain recoverable when removed in the
  follow-up cleanup commit.

.deploy.env.example

@@ -0,0 +1,25 @@
+# Copy this file to `.deploy.env` and fill in your values.
+# `.deploy.env` is gitignored — it holds secrets.
+#
+# Usage:  make deploy    (builds + uploads + registers + re-indexes)
+#   or    bin/deploy.sh  (just the deploy step; assumes .s9pk already built)
+
+# --- FileBrowser upload target ---
+# Local URL to your FileBrowser (from the FileBrowser Dashboard → URL column).
+FILEBROWSER_URL=https://immense-voyage.local:51165
+FILEBROWSER_USER=your-filebrowser-user
+FILEBROWSER_PASS=your-filebrowser-pass
+
+# Path on FileBrowser to overwrite (leading slash, relative to FB root).
+FILEBROWSER_PATH=/websites/packages/youtube-summarizer_x86_64.s9pk
+
+# --- Start9 server that hosts the registry ---
+START9_SERVER=https://immense-voyage.local:62185
+
+# --- Public registry ---
+# REGISTRY_URL is the JSON-RPC endpoint of your public registry.
+REGISTRY_URL=https://registry.satsflows.com
+# REGISTRY_PUBLIC_URL is the publicly-reachable URL of the .s9pk file — this
+# is the URL clients download from when they install the package. Your
+# "Websites" service mirrors /websites/packages/ → files.satsflows.com/.
+REGISTRY_PUBLIC_URL=https://files.satsflows.com/youtube-summarizer_x86_64.s9pk