chore(agent): phase roadmap from TODO.md, 5 phases

The four open items in TODO.md become an executable pipeline: 01 the
verification gate (host suites + sanitiser + both firmware envs, and the
hardware contract so no unit blocks on a board nobody is holding), 02 HTTPS
and wss:// with an identity the board generates itself into NVS, 03 session
takeover that always lands disarmed, 04 a responsive page whose safety
statements are pinned before they are trimmed, 05 the phone as a controller
(press-and-hold pad, soft keyboard, modifier latches over a new Q= frame).

TODO.md is cleared to its empty title; the items live in .agents/phases/ now.
AGENTS.md gains the five protocol rules and nothing else.

LLM-Generated: true

AGENTS.md

@@ -12,6 +12,15 @@ the traps are. **Do not fork the protocol or the safety model into `docs/`** —
 drifts, and two paths that can disagree about arming is the exact failure this project keeps
 having to fix (see README, "Ten bugs").
 
+## Phased execution
+
+This repository runs work through `.agents/phases/`:
+
+1. Always read `.agents/PLAN.md` first to understand the project context and goals.
+2. Follow the phased execution protocol in `.agents/phases/`.
+3. Never modify `.agents/PLAN.md` or any files in `.agents/phases/complete/`.
+4. If you need to update any file in `.agents/phases/todo/`, you must ask the user for permission first.
+5. Strictly adhere to the **LOCKED DECISIONS** listed in `.agents/PLAN.md`.
 
 ## The invariants