v0.2.11 — 2-stage security scan + Antigravity engine resolution

What's new

• 2-stage security scan (BYOK LLM judgment) — hephaestus security scan now merges static-rule findings with the user's own LLM judgment (.agentlas/security-llm-judgment.json). Combined verdict = max severity of both stages. --strict blocks BLOCK (exit 1) and now also gates WARN (exit 2) unless --acknowledge-warn.
• Antigravity /hephaestus engine resolution — the workflow now resolves the engine root from the Claude/Codex plugin cache when the workspace has no local package, so /hephaestus works in any project (previously it only looked at workspace-local files and kept saying "install first"). Also installs into both ~/.gemini/antigravity/ and ~/.gemini/antigravity-ide/ data dirs.
• Version sync — marketplace.json was stale at 0.2.9; all manifests unified to 0.2.11.

Updating

Plugin updates are pull-based (no auto-update):
```
claude plugin marketplace update agentlas-core-engine
claude plugin install hephaestus@agentlas-core-engine --force
```
or re-run the one-touch installer.