feat(marketplace): command consolidation + 8 new plugins (v8.1.0 → v9.0.0) [BREAKING]

Phase 1b: Rename all ~94 commands across 12 plugins to /<noun> <action>
sub-command pattern. Git-flow consolidated from 8→5 commands (commit
variants absorbed into --push/--merge/--sync flags). Dispatch files,
name: frontmatter, and cross-reference updates for all plugins.

Phase 2: Design documents for 8 new plugins in docs/designs/.

Phase 3: Scaffold 8 new plugins — saas-api-platform, saas-db-migrate,
saas-react-platform, saas-test-pilot, data-seed, ops-release-manager,
ops-deploy-pipeline, debug-mcp. Each with plugin.json, commands, agents,
skills, README, and claude-md-integration. Marketplace grows from 12→20.

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

plugins/debug-mcp/skills/venv-diagnostics.md

@@ -0,0 +1,89 @@
+# Virtual Environment Diagnostics Skill
+
+Patterns for checking virtual environment health in MCP server directories.
+
+## Check 1: Venv Exists
+
+```bash
+test -d <server_cwd>/.venv && echo "EXISTS" || echo "MISSING"
+```
+
+If missing, the server will fail to start. Fix:
+```bash
+cd <server_cwd> && python3 -m venv .venv
+```
+
+## Check 2: Python Binary Intact
+
+Venvs can break when the system Python is upgraded (symlink becomes dangling).
+
+```bash
+<server_cwd>/.venv/bin/python --version 2>&1
+```
+
+If error contains "No such file or directory" despite .venv existing, the symlink is broken.
+
+Fix:
+```bash
+cd <server_cwd> && rm -rf .venv && python3 -m venv .venv && .venv/bin/pip install -r requirements.txt
+```
+
+**IMPORTANT:** Never delete .venv without explicit user approval. Show the diagnosis and ask user to confirm the fix.
+
+## Check 3: Requirements Satisfied
+
+Compare requirements.txt with installed packages:
+
+```bash
+cd <server_cwd> && .venv/bin/pip freeze > /tmp/installed.txt
+```
+
+Then diff against requirements.txt:
+- **Missing packages:** In requirements but not installed
+- **Version mismatch:** Installed version does not satisfy requirement specifier
+- **Extra packages:** Installed but not in requirements (usually OK, may indicate stale venv)
+
+Quick check:
+```bash
+cd <server_cwd> && .venv/bin/pip check 2>&1
+```
+
+This reports broken dependencies (missing or incompatible versions).
+
+## Check 4: Module Import Test
+
+Verify the server's main module can be imported:
+
+```bash
+cd <server_cwd> && .venv/bin/python -c "import mcp_server.server" 2>&1
+```
+
+Common failures:
+| Error | Cause | Fix |
+|-------|-------|-----|
+| `ModuleNotFoundError: No module named 'mcp'` | MCP SDK not installed | `pip install mcp` |
+| `ModuleNotFoundError: No module named '<pkg>'` | Missing dependency | `pip install -r requirements.txt` |
+| `ImportError: cannot import name 'X'` | Version mismatch | `pip install --upgrade <pkg>` |
+| `SyntaxError` | Python version too old | Check `python3 --version` >= 3.10 |
+
+## Check 5: Broken Symlinks
+
+Find broken symlinks in the venv:
+
+```bash
+find <server_cwd>/.venv -type l ! -exec test -e {} \; -print 2>/dev/null
+```
+
+Any output indicates broken symlinks that may cause import failures.
+
+## Health Summary Format
+
+```
+### Venv: <server_name>
+- Directory: EXISTS
+- Python: 3.11.2 (OK)
+- Packages: 12 installed, 10 required, 0 missing
+- Import: OK
+- Broken symlinks: 0
+- Status: HEALTHY
+```