feat(ultraplan-local): v2.2.0 — /ultra-cc-architect-local

New optional command between /ultraresearch-local and /ultraplan-local that
matches brief+research against Claude Code features (hooks, subagents, skills,
output-styles, MCP, plan-mode, worktrees, background-agents) and produces an
architecture note with brief-anchored rationale plus explicit gaps.

Added:
- commands/ultra-cc-architect-local.md (--project, --fg, --quick, --no-gaps)
- agents/architect-orchestrator.md (opus) — 6-phase background orchestrator
- agents/feature-matcher.md (sonnet) — fallback-ranked feature proposals
- agents/gap-identifier.md (sonnet) — 4 gap classes with issue-ready drafts
- agents/architecture-critic.md (sonnet) — hallucination gate as BLOCKER
- skills/cc-architect-catalog/ — SKILL.md + 10 seed entries (reference/pattern)

Changed (non-breaking):
- commands/ultraplan-local.md — auto-discovers architecture/overview.md
- agents/planning-orchestrator.md — cross-references cc_features_proposed
- plugin.json — 2.1.0 → 2.2.0, description, cc-architecture keyword
- CHANGELOG, README, CLAUDE.md (plugin + marketplace root)

Pipeline becomes brief → research → architect → plan → execute. Architect is
optional; existing project dirs keep working unchanged.

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

skills/cc-architect-catalog/plan-mode-reference.md

@@ -0,0 +1,65 @@
+---
+name: plan-mode-reference
+description: CC plan mode — read-only planning phase before implementation, with explicit user approval gate.
+layer: reference
+cc_feature: plan-mode
+source: https://docs.claude.com/en/docs/claude-code/plan-mode
+concept: planning-before-execution
+last_verified: 2026-04-18
+ngram_overlap_score: null
+review_status: approved
+---
+
+# Plan Mode — Reference
+
+Plan mode is a built-in state where Claude operates read-only and
+produces an implementation plan instead of executing it. The user
+reviews the plan, then either approves it to transition to
+implementation or iterates.
+
+## State machine
+
+1. **Plan mode entered** — user triggers it (Shift+Tab twice, `/plan`,
+   or harness-initiated) or Claude calls `EnterPlanMode`.
+2. **Read-only operation** — Claude can read files, search, run
+   analysis. Writes, edits, and commits are blocked by the harness.
+3. **Plan produced** — Claude presents a plan via `ExitPlanMode` or
+   equivalent.
+4. **User reviews** — accepts, rejects, or iterates.
+5. **Exit** — on acceptance, mode returns to normal (edits allowed).
+
+## What plan mode guarantees
+
+- No writes during the plan phase. Even if Claude tries, the harness
+  denies write tools.
+- A structured handoff: the plan is a message the user sees before
+  anything happens.
+
+## What plan mode does not guarantee
+
+- Plan quality. Plan mode is a *gate*, not a *reviewer*. A bad plan
+  still passes if the user approves it.
+- Scope locking. After exit, Claude can do whatever the new prompts
+  ask — plan mode is a phase, not a contract.
+
+## When to opt into plan mode
+
+- Tasks touching multiple files or modules where the order and file
+  list matter.
+- Refactors where the first wrong edit is expensive to undo.
+- Unfamiliar codebases where planning surfaces missing context.
+
+## When to skip plan mode
+
+- Single-file trivial changes.
+- Tasks already specified by a detailed plan from another tool
+  (e.g., an `ultraplan-local` plan.md) — planning twice is waste.
+
+## Relationship to /ultra* planning
+
+- `/ultraplan-local` produces a *plan artifact* that outlives the
+  session. Plan mode produces an *in-conversation plan* that does not
+  survive `/clear`.
+- They compose: use plan mode to sketch at session start, then run
+  `/ultraplan-local` to get the durable, reviewable, machine-readable
+  plan with manifests.