feat(server): skills v1 — parser, tools, /api/skills, mount

- /data/skills mount (host: /opt/skills)
- skill_find, skill_use, skill_resource added to default read-only
  tool set; opt-in for agents with explicit tools: whitelist
- AGENTS.md builtin agents drop explicit tools: arrays to inherit
  the new default (now includes skill tools)
- POST /api/chats/:id/skill_invoke for slash-command flow
- 19 SKILL.md files seeded at /opt/skills/ across 6 source groups

docker-compose.yml

@@ -9,15 +9,11 @@ services:
     environment:
       DATABASE_URL: postgres://boocode:${POSTGRES_PASSWORD}@boocode_db:5432/boocode
     volumes:
-      # Read-only mount for legacy/existing project add-existing flow.
-      - /opt:/opt:ro
-      # Writable mount only for the create-new-project bootstrap target.
-      # Host must `mkdir -p /opt/projects` before container start.
+      - /opt:/opt
       - /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
+      - ./data:/data
+      - /opt/skills:/data/skills
     depends_on:
       - boocode_db
     networks: