Remove claude-agent's Matrix presence entirely — Hermes is the only agent in Matrix

By request: one agent in Matrix, not several. Removes matrixBot.js,
router.js (chat-vs-code-task classifier), litellm.js (claude-agent's own
LiteLLM client), the matrix-bot-sdk dependency, runChatTask() and its
gitea.js branch/PR helpers (createBranch/createPullRequest — only ever
called from the now-removed chat flow), and every Matrix/LiteLLM env var
from claude-agent's compose service.

claude-agent already left the control room manually before this merge.
It keeps its Gitea-webhook-triggered PR review, which never touched Matrix
or LiteLLM to begin with.

Makes PR #12 (the claude-bot/Hermes cross-reply cascade fix) moot — the
bug can't happen once claude-agent has no Matrix client at all. Close #12
without merging once this lands.

docker-compose.yml

@@ -94,9 +94,10 @@ services:
     command: ["gateway", "run"]
 
   claude-agent:
+    # Gitea PR-review only now — no Matrix presence (see hermes above; only one agent
+    # is meant to be in Matrix). Still triggered by Gitea's pull_request webhook and
+    # posts review comments there, entirely independent of Matrix/LiteLLM.
     image: ${GITEA_REGISTRY_IMAGE}
-    depends_on:
-      - litellm
     container_name: claude-agent
     restart: unless-stopped
     # Explicit vars, not env_file: .env — Portainer's git-based stack deploy clones the
@@ -109,16 +110,6 @@ services:
       # Claude subscription (Pro/Max) auth via `claude setup-token`, not API billing —
       # Claude Code reads this in preference to ANTHROPIC_API_KEY when both could apply.
       CLAUDE_CODE_OAUTH_TOKEN: ${CLAUDE_CODE_OAUTH_TOKEN}
-      MATRIX_HOMESERVER_URL: ${MATRIX_HOMESERVER_URL}
-      MATRIX_BOT_TOKEN: ${MATRIX_BOT_TOKEN}
-      MATRIX_CONTROL_ROOM_ID: ${MATRIX_CONTROL_ROOM_ID}
-      MATRIX_BOT_USER_ID: ${MATRIX_BOT_USER_ID}
-      KNOWN_REPOS: ${KNOWN_REPOS}
-      # All model calls now go through the local litellm service, not OpenRouter directly —
-      # one gateway for OpenRouter's models (incl. its auto-router) and, for the
-      # claude-subscription route, Anthropic itself via the forwarded OAuth token above.
-      LITELLM_BASE_URL: http://litellm:4000
-      LITELLM_MASTER_KEY: ${LITELLM_MASTER_KEY}
     volumes:
       - agent_workspace:/workspace
     networks: