feat(catalog): T4 — catalog trim + proactive-suggestions.json (Phase A.4)

Shortens frontmatter `description:` in every Claude SKILL.md to a single
lead sentence + (gstack) tag. The routing prose ("Use when asked to...",
"Proactively suggest...") and voice triggers move to a "## When to invoke"
body section so they remain discoverable inside the skill. A per-run
registry at scripts/proactive-suggestions.json aggregates the routing/
voice text for all 52 skills so agents can pull guidance on demand
without paying for it in the always-loaded catalog.

Build flag --catalog-mode=full restores v1.44 legacy behavior (full
multi-line descriptions in frontmatter). Default is trim.

splitCatalogDescription() extracts: lead sentence, routing paragraphs,
voice-triggers line, (gstack) tag presence. Short descriptions (<120
chars, already trimmed) are skipped via a guard so re-runs are idempotent.

Measured impact (vs v1.44.1 baseline):
- Catalog tokens (sum of description bytes / 4): 9,319 → 4,045  (-56.6%)
- Total SKILL.md corpus bytes:                   2,915 KB → 2,880 KB (-1.2%)
- Routing prose preserved as in-skill "## When to invoke" sections
- 52 skill entries in scripts/proactive-suggestions.json (on-demand registry)

The corpus drop is small because catalog trim MOVES text from frontmatter
to body, it doesn't delete it. The headline win is the catalog: the
always-loaded system prompt surface drops by more than half.

Test plan:
- bun test test/gen-skill-docs.test.ts: 389 pass, 0 fail
- Manual: ship/SKILL.md frontmatter description is now ONE line ending
  with `(gstack)`; allowed-tools field on next line (YAML well-formed)
- Manual: scripts/proactive-suggestions.json contains 52 entries
- bun run gen:skill-docs --catalog-mode=full restores legacy behavior

53 files changed (52 SKILL.md across hosts + the new proactive-suggestions.json).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

qa/SKILL.md

@@ -2,16 +2,7 @@
 name: qa
 preamble-tier: 4
 version: 2.0.0
-description: |
-  Systematically QA test a web application and fix bugs found. Runs QA testing,
-  then iteratively fixes bugs in source code, committing each fix atomically and
-  re-verifying. Use when asked to "qa", "QA", "test this site", "find bugs",
-  "test and fix", or "fix what's broken".
-  Proactively suggest when the user says a feature is ready for testing
-  or asks "does this work?". Three tiers: Quick (critical/high only),
-  Standard (+ medium), Exhaustive (+ cosmetic). Produces before/after health scores,
-  fix evidence, and a ship-readiness summary. For report-only mode, use /qa-only. (gstack)
-  Voice triggers (speech-to-text aliases): "quality check", "test the app", "run QA".
+description: Systematically QA test a web application and fix bugs found. (gstack)
 allowed-tools:
   - Bash
   - Read
@@ -29,6 +20,20 @@ triggers:
 <!-- AUTO-GENERATED from SKILL.md.tmpl — do not edit directly -->
 <!-- Regenerate: bun run gen:skill-docs -->
 
+
+## When to invoke this skill
+
+Runs QA testing,
+then iteratively fixes bugs in source code, committing each fix atomically and
+re-verifying. Use when asked to "qa", "QA", "test this site", "find bugs",
+"test and fix", or "fix what's broken".
+Proactively suggest when the user says a feature is ready for testing
+or asks "does this work?". Three tiers: Quick (critical/high only),
+Standard (+ medium), Exhaustive (+ cosmetic). Produces before/after health scores,
+fix evidence, and a ship-readiness summary. For report-only mode, use /qa-only.
+
+Voice triggers (speech-to-text aliases): "quality check", "test the app", "run QA".
+
 ## Preamble (run first)
 
 ```bash