checkpoint: Claude Code integration + implement missing MCP var tools

Add Claude Code conductor commands, MCP server, MMA exec scripts,
and implement py_get_var_declaration / py_set_var_declaration which
were registered in dispatch and tool specs but had no function bodies.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.claude/commands/conductor-new-track.md

@@ -0,0 +1,100 @@
+---
+description: Initialize a new conductor track with spec, plan, and metadata
+---
+
+# /conductor-new-track
+
+Create a new track in the conductor system. This is a Tier 1 (Orchestrator) operation.
+
+## Prerequisites
+- Read `conductor/product.md` and `conductor/product-guidelines.md` for product alignment
+- Read `conductor/tech-stack.md` for technology constraints
+
+## Steps
+
+### 1. Gather Information
+Ask the user for:
+- **Track name**: descriptive, snake_case (e.g., `add_auth_system`)
+- **Track type**: `feat`, `fix`, `refactor`, `chore`
+- **Description**: one-line summary
+- **Requirements**: functional requirements for the spec
+
+### 2. Create Track Directory
+```
+conductor/tracks/{track_name}_{YYYYMMDD}/
+```
+Use today's date in YYYYMMDD format.
+
+### 3. Create metadata.json
+```json
+{
+  "track_id": "{track_name}_{YYYYMMDD}",
+  "type": "{feat|fix|refactor|chore}",
+  "status": "new",
+  "created_at": "{ISO8601}",
+  "updated_at": "{ISO8601}",
+  "description": "{description}"
+}
+```
+
+### 4. Create index.md
+```markdown
+# Track: {Track Title}
+
+- [Specification](spec.md)
+- [Implementation Plan](plan.md)
+```
+
+### 5. Create spec.md
+```markdown
+# {Track Title} — Specification
+
+## Overview
+{Description of what this track delivers}
+
+## Functional Requirements
+1. {Requirement from user input}
+2. ...
+
+## Non-Functional Requirements
+- Performance: {if applicable}
+- Testing: >80% coverage for new code
+
+## Acceptance Criteria
+- [ ] {Criterion 1}
+- [ ] {Criterion 2}
+
+## Out of Scope
+- {Explicitly excluded items}
+
+## Context
+- Tech stack: see `conductor/tech-stack.md`
+- Product guidelines: see `conductor/product-guidelines.md`
+```
+
+### 6. Create plan.md
+```markdown
+# {Track Title} — Implementation Plan
+
+## Phase 1: {Phase Name}
+- [ ] Task: {Description}
+- [ ] Task: {Description}
+
+## Phase 2: {Phase Name}
+- [ ] Task: {Description}
+```
+
+Break requirements into phases with 2-5 tasks each. Each task should be a single atomic unit of work suitable for a Tier 3 Worker.
+
+### 7. Update Track Registry
+If `conductor/tracks.md` exists, add the new track entry.
+
+### 8. Commit
+```
+conductor(track): Initialize track '{track_name}'
+```
+
+## Important
+- Do NOT start implementing — track initialization only
+- Implementation is done via `/conductor-implement`
+- Each task should be scoped for a single Tier 3 Worker delegation