refactor(marketplace): split cc-architect from ultraplan-local into its own plugin

Extract `/ultra-cc-architect-local` and `/ultra-skill-author-local` plus all 7
supporting agents, the `cc-architect-catalog` skill (13 files), the
`ngram-overlap.mjs` IP-hygiene script, and the skill-factory test fixtures
from `ultraplan-local` v2.4.0 into a new `ultra-cc-architect` plugin v0.1.0.

Why: ultraplan-local had drifted into containing two distinct domains — a
universal planning pipeline (brief → research → plan → execute) and a
Claude-Code-specific architecture phase. Keeping them together forced users
to inherit an unfinished CC-feature catalog (~11 seeds) when they only
wanted the planning pipeline, and locked the catalog and the pipeline into
the same release cadence. The architect was already optional and decoupled
at the code level — only one filesystem touchpoint remained
(auto-discovery of `architecture/overview.md`), which already handles
absence gracefully.

Plugin manifests:
- ultraplan-local: 2.4.0 → 3.0.0 (description + keywords updated)
- ultra-cc-architect: new at 0.1.0 (pre-release; catalog is thin, Fase 2/3
  of skill-factory unbuilt, decision-layer empty, fallback list still
  needed)

What stays in ultraplan-local: brief/research/plan/execute commands, all
19 planning agents, security hooks, plan auto-discovery of
`architecture/overview.md` (filesystem-level contract, not code-level).

What moved (28 files via git mv, R100 — full history preserved):
- 2 commands, 8 agents, 1 skill catalog (13 files), 2 scripts, 8 fixtures

Documentation updates: plugin CLAUDE.md and README.md for both plugins,
root README.md (added ultra-cc-architect section, updated ultraplan-local
section), root CLAUDE.md (added ultra-cc-architect to repo-struktur),
marketplace.json (registered ultra-cc-architect), ultraplan-local
CHANGELOG.md (v3.0.0 entry with migration guidance).

Test verification: ngram-overlap.test.mjs passes 23/23 from new location.

Memory updated: feedback_no_architect_until_v3.md now points at the new
plugin and reframes the threshold around catalog maturity rather than an
ultraplan-local milestone.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

plugins/ultra-cc-architect/tests/fixtures/skill-drafter/slug-collision-expected.md

@@ -0,0 +1,159 @@
+# Skill-drafter slug-collision — expected output fixture
+
+This fixture documents the expected confirmation-message shape from
+`skill-drafter` when it detects a slug collision at the catalog root.
+It is a reference fixture — not an auto-executed test — used to
+verify the agent by running a synthetic scenario by hand and
+comparing output against the shapes below.
+
+## Scenario A — no collision (baseline)
+
+### Synthetic input
+
+- **Catalog root:** `skills/cc-architect-catalog/`
+- **Concept JSON (from concept-extractor):**
+  ```json
+  {
+    "cc_feature": "worktrees",
+    "layer": "pattern",
+    "concept": "parallel feature isolation",
+    "description": "Isolate concurrent feature work in per-task worktrees to avoid git race conditions.",
+    "source_path": "/tmp/worktrees-notes.md",
+    "out_of_scope": false
+  }
+  ```
+- **Catalog state at time of run:** no `worktrees-pattern.md` present
+  at catalog root (only `worktrees-reference.md`).
+
+### Expected confirmation output
+
+```
+Drafted: /Users/…/skills/cc-architect-catalog/.drafts/worktrees-pattern.md
+Word count: 312
+Frontmatter: 9 fields, review_status=pending, ngram_overlap_score=null
+Collision: none
+Next: ip-hygiene-checker for IP scoring
+```
+
+No warning block. `Collision: none`.
+
+## Scenario B — approved collision (primary case)
+
+### Synthetic input
+
+- **Catalog root:** `skills/cc-architect-catalog/`
+- **Concept JSON:**
+  ```json
+  {
+    "cc_feature": "hooks",
+    "layer": "pattern",
+    "concept": "observability progressive alerts",
+    "description": "Progressive-alert observability pattern for hook-driven telemetry.",
+    "source_path": "/tmp/hooks-telemetry-notes.md",
+    "out_of_scope": false
+  }
+  ```
+- **Catalog state:** `hooks-pattern.md` exists with
+  `review_status: approved` (the v2.3.0 seed).
+
+### Expected confirmation output
+
+```
+⚠️  Slug collision at catalog root
+   Existing: skills/cc-architect-catalog/hooks-pattern.md (review_status=approved)
+   Draft:    skills/cc-architect-catalog/.drafts/hooks-pattern.md (this run)
+   Risk:     manual `mv` during promotion will silently overwrite the existing file.
+   Suggested qualified slug: hooks-observability-pattern.md
+   Reason for qualifier:     concept handle names "observability" as the named sub-pattern.
+   Action:                   rename the draft before `mv`, or revise the existing baseline.
+
+Drafted: /Users/…/skills/cc-architect-catalog/.drafts/hooks-pattern.md
+Word count: 287
+Frontmatter: 9 fields, review_status=pending, ngram_overlap_score=null
+Collision: approved
+Next: ip-hygiene-checker for IP scoring
+```
+
+The warning is prepended. The draft is still written — the collision
+check is a hint, not a block. `Collision: approved` appears in the
+confirmation for downstream-log parsers.
+
+## Scenario C — soft collision (pending existing)
+
+### Synthetic input
+
+- **Catalog state:** `subagents-pattern.md` exists with
+  `review_status: pending` (a prior draft that was `mv`-ed up without
+  the status being flipped, or a skill-factory auto-merged entry).
+
+### Expected confirmation output
+
+```
+⚠️  Slug collision at catalog root
+   Existing: skills/cc-architect-catalog/subagents-pattern.md (review_status=pending)
+   Draft:    skills/cc-architect-catalog/.drafts/subagents-pattern.md (this run)
+   Risk:     manual `mv` during promotion will silently overwrite the existing file.
+   Suggested qualified slug: subagents-delegation-pattern.md
+   Reason for qualifier:     concept handle centers on "delegation chains".
+   Action:                   rename the draft before `mv`, or revise the existing baseline.
+
+Drafted: /Users/…/skills/cc-architect-catalog/.drafts/subagents-pattern.md
+Word count: 256
+Frontmatter: 9 fields, review_status=pending, ngram_overlap_score=null
+Collision: pending
+Next: ip-hygiene-checker for IP scoring
+```
+
+`Collision: pending` signals a soft collision — the existing file is
+not necessarily a guaranteed baseline. Reviewer decides.
+
+## Scenario D — collision but no good qualifier
+
+### Synthetic input
+
+- **Concept handle:** `generic feature note` (no specific noun)
+- **Catalog state:** `skills-reference.md` exists (approved).
+
+### Expected confirmation output
+
+```
+⚠️  Slug collision at catalog root
+   Existing: skills/cc-architect-catalog/skills-reference.md (review_status=approved)
+   Draft:    skills/cc-architect-catalog/.drafts/skills-reference.md (this run)
+   Risk:     manual `mv` during promotion will silently overwrite the existing file.
+   Suggested qualified slug: none — reviewer must pick one manually.
+   Action:                   rename the draft before `mv`, or revise the existing baseline.
+
+Drafted: /Users/…/skills/cc-architect-catalog/.drafts/skills-reference.md
+Word count: 198
+Frontmatter: 9 fields, review_status=pending, ngram_overlap_score=null
+Collision: approved
+Next: ip-hygiene-checker for IP scoring
+```
+
+The fallback line replaces the "Suggested qualified slug" value.
+`Reason for qualifier` is omitted.
+
+## How to verify against this fixture
+
+This is not an auto-run test. To verify:
+
+1. Stage a synthetic concept JSON matching one of the scenarios above.
+2. Invoke `skill-drafter` via the `Agent` tool with the concept JSON,
+   source path, and catalog root.
+3. Capture the confirmation output.
+4. Compare structurally against the corresponding scenario. The exact
+   word counts and paths will differ; the warning block, collision
+   field, and suggested-slug line are the load-bearing shapes.
+
+If a future change alters the confirmation format, update this file
+alongside the agent prompt so the two remain in lockstep.
+
+## Why a reference fixture and not a unit test
+
+`skill-drafter` is a prompt-driven Sonnet agent. There is no in-repo
+harness that executes prompts deterministically, so a unit test is
+not practical. The reference fixture is the next-best anchor — it
+documents the expected shape for human verification and for
+downstream agents that parse the confirmation (e.g., the
+skill-author-orchestrator's summary phase).