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-status.md

@@ -0,0 +1,32 @@
+---
+description: Show current conductor track status — active tracks, phases, pending tasks
+---
+
+# /conductor-status
+
+Read the conductor track registry and all active tracks, then report current project state.
+
+## Steps
+
+1. Read `conductor/tracks.md` for the track registry
+2. For each track directory in `conductor/tracks/`:
+   - Read `metadata.json` for status
+   - Read `plan.md` and count: total tasks, completed `[x]`, in-progress `[~]`, pending `[ ]`
+   - Identify the current phase (first phase with `[~]` or `[ ]` tasks)
+3. Read `JOURNAL.md` last 3 entries for recent activity context
+
+## Output Format
+
+Present a summary table:
+
+```
+| Track | Status | Phase | Progress | Last SHA |
+|-------|--------|-------|----------|----------|
+```
+
+Then for each in-progress track, list the specific next pending task.
+
+## Important
+- This is READ-ONLY — do not modify any files
+- Report exactly what the plan.md files say
+- Flag any discrepancies (e.g., metadata says "new" but plan.md has [x] tasks)