feat(ultraplan-local): v2.3.1 — qualified slug convention for cc-architect-catalog

Resolves v2.3.0 dogfood collision: skill-factory produced a
specialized hooks-pattern.md draft that would have overwritten the
generic seed. Qualified slugs let one feature host multiple named
patterns at different abstraction levels.

Slug convention: <cc_feature>[-<qualifier>]-<layer>.md. Unqualified =
canonical baseline. Qualified = sub-pattern (e.g., hooks-observability-
pattern.md) that does not displace the baseline.

Changes:
- SKILL.md: slug convention section, coverage-table qualified column,
  matcher logic for N patterns per feature, modification rules cover
  qualified-vs-canonical choice and collision handling.
- feature-matcher: catalog map is cc_feature -> {layer -> [skills]};
  selection rules (baseline by default, qualified when justified,
  multi-skill when non-overlapping); supporting_skill accepts list.
- gap-identifier: adds pattern_count[cc_feature] to coverage audit.
- architecture-critic: supporting-skill verification — every cited
  skill name must exist in the catalog (blocker severity).
- First qualified skill: hooks-observability-pattern.md (promoted from
  .drafts/, source ai-psychosis/README.md, ngram-overlap 0.01).
- Version bump 2.3.0 -> 2.3.1 across plugin.json, badges, table, root
  CLAUDE.md, CHANGELOG.

Non-breaking: existing unqualified slugs keep working, no cc_feature
taxonomy changes, hallucination gate unchanged.

plugins/ultraplan-local/CLAUDE.md

@@ -123,6 +123,16 @@ Architect sits between `/ultraresearch-local` and `/ultraplan-local`. It matches
 
 **CC-feature catalog skill:** The architect phase loads the `cc-architect-catalog` skill, which indexes Claude Code primitives (hooks, subagents, skills, output styles, MCP, plan mode, worktrees, background agents) across three layers: `reference` (how a feature works), `pattern` (when to reach for it), `decision` (adoption heuristics). The `feature-matcher` agent only proposes features covered by the catalog *or* an explicit fallback list — a hallucination gate that `architecture-critic` enforces as BLOCKER severity. The `gap-identifier` agent emits issue-ready drafts for missing catalog entries so the catalog grows with real usage rather than speculation. The catalog lives at `skills/cc-architect-catalog/`.
 
+**Slug convention (v2.3.1):** catalog files follow `<cc_feature>[-<qualifier>]-<layer>.md`.
+
+- **Unqualified slugs** (e.g., `hooks-pattern.md`) are the canonical baseline — one per `(feature, layer)` pair, covering generic shapes and decision-heuristics for the feature.
+- **Qualified slugs** (e.g., `hooks-observability-pattern.md`) cover specific named sub-patterns. Zero-or-more per `(feature, layer)` pair. The qualifier MUST be kebab-case and descriptive (`observability`, `migration`, `multi-tenant`).
+- **Matcher logic:** `feature-matcher` builds `cc_feature → {layer → [skills]}` and prefers the unqualified baseline when the brief does not specifically justify a variant. Multiple skills can be proposed together when they cover non-overlapping aspects of the same feature.
+- **Critic enforcement:** `architecture-critic` verifies every cited `supporting_skill` name exists as a real file in the catalog (blocker severity). The `cc_feature` hallucination gate is unchanged — still validates against the taxonomy, not slugs.
+- **Collision handling:** skill-factory drafts that would overwrite an approved slug are a hard error. Resolution is either to qualify the new slug or revise the existing baseline.
+
+Seeds v2.3.1: 11 skills across 8 features — one qualified pattern (`hooks-observability-pattern.md`, promoted from `ai-psychosis/README.md`, ngram-overlap 0.01, approved). Decision-layer intentionally empty pending skill-factory Fase 2.
+
 ## State
 
 All artifacts in one project directory (default):