SDLC init

Writes the lifecycle down once, so every later skill and every agent session can read where a change is and what comes next.

The stages: request, RFC, decision, build, review, test, gate, release, observe, incident, and back to request.

Steps

1. Run the audit first if no docs/sdlc.md exists: /sdlc:sdlc-audit. Its evidence fills most of the table.
2. Find the installed modules from the files they leave in the repository: