Add /design round-trip and design-checker agent to the fleet

Design/branding for any user-facing repo becomes a vendor-neutral on-disk
contract — design/DESIGN.md (nine-section brief) + design/tokens.tokens.json
(W3C DTCG tokens) — that every agent reads before building UI. Claude Design
is the interchangeable cloud front-end, never a dependency.

- /design (main-thread command): inspiration-first scoping -> BRIEF.md -> user
  drives the cloud step -> distill the export back into the contract. Phase-C
  token distillation is agent-mediated because the export is inline-hardcoded
  HTML/CSS, not DTCG.
- design-checker (read-only subagent): audits a repo's UI against its own
  committed contract; says "run /design first" when none exists.
- /new-project scaffolds design/ for user-facing projects.

AGENTS.md

@@ -17,10 +17,10 @@ The global layer lives here and is wired into `~/.claude` by **directory symlink
 file added under `adapters/` is live immediately — no per-file linking:
 
 - `~/.claude/commands` → `adapters/claude/commands/` — global slash commands (`/retrofit`,
-  `/handoff`, `/full-eval`, `/capture`, `/triage`, `/roundup`, `/new-project`).
+  `/handoff`, `/full-eval`, `/capture`, `/triage`, `/roundup`, `/new-project`, `/design`).
 - `~/.claude/agents` → `adapters/claude/agents/` — global subagents (reviewer, evaluator,
   security-auditor, doc-auditor, exerciser, researcher, janitor, portability-checker,
-  start9-spec-checker).
+  start9-spec-checker, design-checker).
 - `~/.claude/CLAUDE.md` → `how-i-work.md` — my universal preferences, loaded every session.
   (Distinct from this repo's *root* `CLAUDE.md`, which → `AGENTS.md`: same filename, different
   scopes — global preferences vs. this repo's orientation.)
@@ -92,7 +92,14 @@ should carry this so any vendor's agent surfaces pending items at session start:
   in `adapters/claude/`, symlinked into `~/.claude`). The repo dogfoods its own standard:
   inbox-check line, deny-by-default `.gitignore`, relative symlinks, capture→triage→roadmap loop.
 - `/roundup` writes a tracked `STATUS.md` snapshot each run (overwritten, committed + pushed —
-  diffable over time); latest snapshot dated 2026-06-15.
+  diffable over time); latest snapshot dated 2026-06-16.
+- **Design system built (2026-06-16, ROADMAP item 8).** `/design` (main-thread command) runs
+  the inspiration-first design round-trip → a vendor-neutral on-disk contract (`design/DESIGN.md`
+  nine-section brief + `design/tokens.tokens.json` DTCG tokens); `design-checker` (read-only
+  subagent) audits a repo's UI against its own contract. Claude Design (cloud-only/experimental)
+  is the interchangeable front-end, never a dependency — its export is inline-hardcoded HTML/CSS,
+  so Phase-C token distillation is agent-mediated (research-verified 2026-06-16). `/new-project`
+  now scaffolds `design/` for user-facing projects.
 - `/new-project` is the inverse of `/retrofit`: workshops a captured `(new)` idea into a
   standards-compliant repo and publishes to Gitea via a manual-create gate; the stack quality
   gate is deferred to a future `/harden`. Now carries a **form-factor gate** (is this even a
@@ -123,7 +130,9 @@ should carry this so any vendor's agent surfaces pending items at session start:
   trimming (per-repo AGENTS.md files aren't bloated, and in-repo copies aid self-containment).
 - **Next steps:** (1) the cross-repo quality-gate standard + `/harden` (ROADMAP item 1 — also
   unblocks `/new-project`'s deferred quality-gate step); (2) the non-git-folder sweep under
-  `~/Projects` (item-6 residual; count ~13).
+  `~/Projects` (item-6 residual; count ~13); (3) first live `/design` run + `design-checker`
+  backfill on a user-facing repo, which will also confirm what Claude Design's export actually
+  contains and let us tune Phase-C distillation (ROADMAP item 8 remaining options).
 - Queued elsewhere / specced-not-built: the `ten31-transcripts` mini-retrofit and a new
   `(ten31-database)` networking-doc fix wait in `INBOX.md` for those repos' `/triage`; the
   SessionStart hook (item 3) and inbox-line bootstrap threading (item 4) remain on the ROADMAP.