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>

plugins/ultraplan-local/skills/cc-architect-catalog/mcp-reference.md

@@ -0,0 +1,72 @@
+---
+name: mcp-reference
+description: Model Context Protocol — external tools and resources exposed to Claude via MCP servers.
+layer: reference
+cc_feature: mcp
+source: https://docs.claude.com/en/docs/claude-code/mcp
+concept: mcp-tool-protocol
+last_verified: 2026-04-18
+ngram_overlap_score: null
+review_status: approved
+---
+
+# MCP — Reference
+
+Model Context Protocol (MCP) is the protocol Claude Code uses to talk
+to external tool servers. An MCP server advertises *tools* and
+*resources*; Claude Code surfaces them to Claude as callable tools.
+
+## Architecture
+
+- **MCP server** — a process (local or remote) that implements the
+  protocol. Can be written in any language. Communicates over stdio,
+  HTTP, or WebSocket.
+- **Transport** — stdio (local subprocess), SSE/HTTP (remote), or
+  WebSocket. Stdio is the default for local servers.
+- **Tools** — callable functions the server exposes. Each has a name,
+  description, and JSON schema for inputs.
+- **Resources** — readable entities the server exposes (files,
+  database rows, API responses). Addressed by URI.
+- **Prompts** — optional; MCP can expose templated prompts.
+
+## Configuration
+
+MCP servers are declared in:
+
+- `.mcp.json` — project-level MCP config.
+- `~/.claude.json` or equivalent — user-level.
+- Plugin-bundled — a plugin can ship its own MCP server.
+
+Each entry specifies command, args, transport, and optional auth.
+
+## Tool naming
+
+Tools from MCP servers appear to Claude with a namespaced name:
+`mcp__<server-name>__<tool-name>`. This keeps names collision-free
+across servers.
+
+## Permissions
+
+- `allowed-tools` in settings or plugin frontmatter can include MCP
+  tools by full name.
+- Some MCP servers require OAuth or API keys; those are configured in
+  the server's own config, not Claude's.
+
+## Common uses
+
+- Exposing internal APIs to Claude without hand-wrapping them (one
+  generic MCP server → many tools).
+- Cross-language tool servers (Python tool called from Claude Code
+  running in Node).
+- Sandboxed access to external services with explicit scoping.
+
+## Failure modes
+
+- Server not running → tool calls fail; Claude sees an error string.
+- Server misbehaves → tool returns wrong schema; Claude may retry or
+  hallucinate.
+- Authentication drift → 401s look like transient errors; diagnose by
+  checking the server directly.
+- Security: an MCP server runs with the permissions of its own
+  process. A malicious server is a supply-chain risk; audit before
+  enabling.