v1.8.1: global agents + parser robustness + WS reconnect toast

Builtins move out of code into /data/AGENTS.md (always-on, mounted ro
into the container); per-project AGENTS.md is now an optional override.
agents.ts merges global + project entries with project-wins-by-name and
caches per-source mtimes (60s TTL). Parser switches to per-block
try/catch and returns AgentsResponse { agents, errors[] } so one
malformed block no longer fails the file. AgentPicker shows a
non-blocking amber chip listing skipped blocks and only fires a gray
toast when zero agents loaded.

WS reconnect UX (useUserEvents + useSessionStream) now silent on the
first disconnect; createWsReconnectToast escalates to gray after 3
failures or 15 s, then to red with a Retry Now action after 60 s.
useSessionStream also gained the exponential-backoff reconnect it was
missing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docker-compose.yml

@@ -15,6 +15,9 @@ services:
       # Host must `mkdir -p /opt/projects` before container start.
       - /opt/projects:/opt/projects:rw
       - ./secrets/boocode_gitea:/root/.ssh/id_ed25519:ro
+      # v1.8.1: global agents file. Host seeds it once before deploy:
+      # cp /opt/boocode/AGENTS.md /opt/boocode/data/AGENTS.md
+      - ./data:/data:ro
     depends_on:
       - boocode_db
     networks: