docs: handoff, session log and pointers to the contract

docs/HANDOFF.md is the starting point for the next maintainer;
docs/superpowers/notes/2026-11-11-session-log.md records the day.
AGENTS.md, CLAUDE.md and README now point maintainers to the handoff
and to docs/contract.md.

Co-Authored-By: Claude Fable 5.2 <noreply@anthropic.com>

README.md

@@ -157,7 +157,7 @@ e2e/                      maintainer tooling: Playwright end-to-end tests of eve
 
 ## For maintainers
 
-These scripts check the course itself; students do not need them. Run them from the repository root.
+These scripts check the course itself; students do not need them. Run them from the repository root. The rules the course code must follow are in [docs/contract.md](docs/contract.md); the current state and working method are in [docs/HANDOFF.md](docs/HANDOFF.md).
 
 | Script | What it checks |
 |---|---|