fix: Remove Matrix integration — notifications move to forge + OpenClaw (#732)

Remove all Matrix/Dendrite infrastructure:
- Delete lib/matrix_listener.sh (long-poll daemon), lib/matrix_listener.service
  (systemd unit), lib/hooks/on-stop-matrix.sh (response streaming hook)
- Remove matrix_send() and matrix_send_ctx() from lib/env.sh
- Remove MATRIX_HOMESERVER auto-detection, MATRIX_THREAD_MAP from lib/env.sh
- Remove [matrix] section parsing from lib/load-project.sh
- Remove Matrix hook installation from lib/agent-session.sh
- Remove notify/notify_ctx helpers and Matrix thread tracking from
  dev/dev-agent.sh and action/action-agent.sh
- Remove all matrix_send calls from dev-poll.sh, phase-handler.sh,
  action-poll.sh, vault-poll.sh, vault-fire.sh, vault-reject.sh,
  review-poll.sh, review-pr.sh, supervisor-poll.sh, formula-session.sh
- Remove Matrix listener startup from docker/agents/entrypoint.sh
- Remove append_dendrite_compose() and setup_matrix() from bin/disinto
- Remove --matrix flag from disinto init
- Clean Matrix references from .env.example, projects/*.toml.example,
  formulas/*.toml, AGENTS.md, BOOTSTRAP.md, README.md, RESOURCES.md,
  PHASE-PROTOCOL.md, and all agent AGENTS.md/PROMPT.md files

Status visibility now via Codeberg PR/issue activity. Human interaction
via vault items through forge. Proactive alerts via OpenClaw heartbeats.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

action/AGENTS.md

@@ -18,16 +18,14 @@ session, and spawns `action-agent.sh <issue-number>`.
 **Session lifecycle**:
 1. `action-poll.sh` finds open `action` issues with no active tmux session.
 2. Spawns `action-agent.sh <issue_num>`.
-3. Agent creates Matrix thread, exports `MATRIX_THREAD_ID` so Claude's output streams to the thread via a Stop hook (`on-stop-matrix.sh`).
-4. Agent creates tmux session `action-{project}-{issue_num}`, injects prompt (formula + prior comments + phase protocol).
-5. Agent enters `monitor_phase_loop` (shared with dev-agent via `dev/phase-handler.sh`).
-6. **Path A (git output):** Claude pushes branch → `PHASE:awaiting_ci` → handler creates PR, polls CI → injects failures → Claude fixes → push → re-poll → CI passes → `PHASE:awaiting_review` → handler polls reviews → injects REQUEST_CHANGES → Claude fixes → approved → merge → cleanup.
-7. **Path B (no git output):** Claude posts results as comment, closes issue → `PHASE:done` → handler cleans up (kill session, docker compose down, remove temp files).
-8. For human input: Claude sends a Matrix message and waits; the reply is injected into the session by `matrix_listener.sh`.
+3. Agent creates tmux session `action-{project}-{issue_num}`, injects prompt (formula + prior comments + phase protocol).
+4. Agent enters `monitor_phase_loop` (shared with dev-agent via `dev/phase-handler.sh`).
+5. **Path A (git output):** Claude pushes branch → `PHASE:awaiting_ci` → handler creates PR, polls CI → injects failures → Claude fixes → push → re-poll → CI passes → `PHASE:awaiting_review` → handler polls reviews → injects REQUEST_CHANGES → Claude fixes → approved → merge → cleanup.
+6. **Path B (no git output):** Claude posts results as comment, closes issue → `PHASE:done` → handler cleans up (kill session, docker compose down, remove temp files).
+7. For human input: Claude writes `PHASE:escalate`; human responds via vault/forge.
 
 **Environment variables consumed**:
 - `FORGE_TOKEN`, `FORGE_REPO`, `FORGE_API`, `FORGE_URL`, `PROJECT_NAME`, `FORGE_WEB`
-- `MATRIX_TOKEN`, `MATRIX_ROOM_ID`, `MATRIX_HOMESERVER` — Matrix notifications + human input
 - `ACTION_IDLE_TIMEOUT` — Max seconds before killing idle session (default 14400 = 4h)
 - `ACTION_MAX_LIFETIME` — Max total session wall-clock seconds (default 28800 = 8h); caps session independently of idle timeout