fix: make bot startup resilient (self-healing state, gated cogs, loud failures)

Container/native startup died silently on any missing file/service. Now:

constants.py - self-healing runtime layout at import:
- create missing dirs (log dir, LOGSTORE, GRAPHICS_PATH, MUSIC_FOLDER)
- seed missing state files from the repo templates shipped next to
  constants.py (settings/system_gpt/pamiec/pamiec_muzyki/accident_log),
  falling back to safe empty JSON; existing files are NEVER overwritten

bot.py:
- log to stdout too, so 'docker logs' finally shows the crash reason
- missing Discord token = loud sys.exit with mount/env instructions
  (was: silent return -> container crash-loop with empty logs)
- every cog loads independently (one broken cog = skipped with traceback,
  bot continues)
- musician/librarian cogs are health-gated: enabled only when the service
  answers HTTP; a watchdog re-checks every 5 min and enables them the
  moment the service comes alive (no restart needed); tree re-synced
- on_ready reconnects no longer re-load extensions

requirements_conan.txt + Dockerfile.bot: aiomcrcon (Python <=3.11 only)
moved to best-effort extras so the 3.13 image builds clean and the
conanjurer cog stays dormant without it.

DOCKER_PROXMOX.md: startup model (core vs gated cogs) + crash-loop
troubleshooting incl. the 'disappearing files' checklist (nothing in the
stack deletes host files; bind mount = live state).

Verified: fresh-volume seeding creates dirs+templates, existing files
untouched, missing-token exits with FATAL message, health-gating logic
(stub-based runpy tests).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/deployment/DOCKER_PROXMOX.md

@@ -96,8 +96,47 @@ docker compose -f docker/compose.bot.yaml up -d --build
 docker logs -f conjurer-bot
 ```
 
-Look for `Loading … module done` for each cog, `Loading conanjurer commands
-module done`, and `All systems: operational`.
+Look for `Extension loaded: …` for each cog and `All systems: operational`.
+
+### 1e. Startup model: core cogs vs service-gated cogs
+
+The bot **always** starts with the cogs that depend on nothing but itself
+(administration, AI, other, latex, voice, conanjurer). Cogs that need a
+sibling service are **health-gated**:
+
+| Group | Cogs | Enabled when |
+|-------|------|--------------|
+| musician | `music_commands`, `radio_commands`, `file_search_commands` | `GET {FILE_SERVICE}/mp3` answers |
+| librarian | `librarian_commands` | librarian answers HTTP at all |
+
+When a service is down its cogs stay disabled (commands simply don't exist)
+and the log says so. A watchdog re-checks every 5 minutes and enables the
+cogs the moment the service starts answering — no bot restart needed.
+A single broken cog (missing pip package, bad import) is skipped with a full
+traceback in the log; it never takes the whole bot down.
+
+### 1f. Troubleshooting a crash-looping container
+
+`docker logs conjurer-bot` now shows the real reason (the bot logs to stdout
+as well as the rotating file). The most common cases:
+
+- **`FATAL: Discord token missing`** — the secrets mount is missing/empty or
+  `CONJURER_NETRC_FILE` points elsewhere. Check:
+  `docker inspect -f '{{json .Mounts}}' conjurer-bot | jq` and
+  `docker exec conjurer-bot ls -la /secrets/` (after a manual
+  `docker run … sleep infinity` if it crash-loops too fast).
+- **Missing state files** — not fatal anymore: missing dirs are created and
+  missing JSON state is seeded from the repo templates baked into the image
+  (existing files are never overwritten). Fix the mount at your leisure.
+
+**About files "disappearing" from `/srv/conjurer/...`:** nothing in this stack
+deletes host files — the entrypoint and the bot only ever *create* missing
+files. With a bind mount, `/srv/conjurer/data` **is** the live state (not an
+installation staging area): don't delete it after a successful install.
+If files vanished, the usual suspects are `docker compose down -v` (only
+affects *named* volumes, not binds), a re-provisioned VM, or copying the files
+to a different path than the one in the compose `volumes:` line — verify with
+`docker inspect -f '{{json .Mounts}}' conjurer-bot`.
 
 ---