SKILL.md now analyses the target agent's codebase first (Step 0) and
routes to the correct integration path:
- Path A: Production (PostgreSQL + Langfuse + feedback loop)
- Path B: PostgreSQL only (no Langfuse)
- Path C: Lightweight (InMemoryTraceStore, no DB)

Covers 3 injection methods: LangGraph node, prompt enhancement, PlanEngine.
All 12 tests pass in clean sandbox (paths, methods, edge cases).

Co-authored-by: Cursor <cursoragent@cursor.com>