skill-concierge setup

First-time bootstrap (and post-update refresh) for the vendored skill-search engine. setup.sh is idempotent — safe to re-run any time.

Prerequisites

Python 3.10–3.12 on PATH (or set SKILL_PYTHON=/path/to/python3.12). No Docker: the vector store is the local index owner (python -m skill_search.index_owner from the venv, one SQLite file), which setup.sh starts itself.

If Python is missing, tell the user and stop — setup.sh cannot proceed without it.

Run the bootstrap from the plugin root:
```
bash "$CLAUDE_PLUGIN_ROOT/setup.sh"
```
(When working from a git clone instead, cd into the repo and run ./setup.sh.) It performs four idempotent steps: stable venv + deps → (re)start the index owner → build/refresh the index (discovers skills from every supported harness's skill roots) and the actionability-gate corpus → apply curated overrides to ~/.claude/settings.json (backed up first; Claude Code only — a harmless no-op when run from Codex). Setup never builds the keep-off map: it is consent-only (ADR-0077).
De-duplicate any prior user-scope MCP so only the bundled one runs:
```
claude mcp remove skill-search -s user
```
Restart Claude Code so the MCP server and the settings overrides take effect.
Verify the install:
```
python3 "$CLAUDE_PLUGIN_ROOT/scripts/doctor.py"
```
Expect status: OK. In Claude Code, /mcp should list skill-concierge:skill-search as connected. If anything is degraded, hand off to the skill-concierge:doctor skill.

After any plugin update (/plugin marketplace update + reinstall) — refreshes the engine copy in the stable venv and rebuilds the index.
When the owner's index file (~/.cache/skill-search/index.sqlite) or the venv was wiped.

The venv lives at ~/.claude/skill-concierge/venv (outside the plugin cache, so it survives reinstalls — ADR-0004). Override with SKILL_CONCIERGE_VENV.
setup.sh reads the embedder + store URL from .mcp.json so the built index can never diverge from the model the live MCP uses.