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>

constants.py

@@ -202,6 +202,65 @@ PORT_ADDRESS = int(os.getenv("CONJURER_DISCORD_PORT", "5000"))
 API_SHARED_KEY = os.getenv("CONJURER_API_KEY", "")
 
 
+# *=========================================== Self-healing runtime layout
+# A fresh host/volume must never kill the bot at import time. Missing
+# directories are created and missing state files are seeded - first from the
+# templates shipped alongside this file (repo checkout / docker image), then
+# from a safe empty structure. Existing files are never touched, so preserved
+# history always wins.
+
+_TEMPLATE_DIR = os.path.dirname(os.path.abspath(__file__))
+
+
+def _ensure_dir(path: str) -> None:
+    if not path:
+        return
+    try:
+        os.makedirs(path, exist_ok=True)
+    except OSError as exc:
+        logger.warning("Cannot create directory %s: %s", path, exc)
+
+
+def _seed_file(path: str, template_name: str, empty_content: str) -> None:
+    """Create *path* from the repo template (or *empty_content*) if missing."""
+    if not path or os.path.exists(path):
+        return
+    _ensure_dir(os.path.dirname(path) or ".")
+    template = os.path.join(_TEMPLATE_DIR, template_name)
+    try:
+        if os.path.exists(template) and os.path.abspath(template) != os.path.abspath(path):
+            import shutil
+
+            shutil.copyfile(template, path)
+            logger.warning("Seeded missing %s from repo template", path)
+        else:
+            with open(path, "w", encoding=ENCODING) as handle:
+                handle.write(empty_content)
+            logger.warning("Created missing %s as empty state", path)
+    except OSError as exc:
+        logger.warning("Cannot seed %s: %s", path, exc)
+
+
+def _ensure_runtime_layout() -> None:
+    for directory in (
+        os.path.dirname(LOGFILE) or ".",
+        LOGSTORE,
+        GRAPHICS_PATH,
+        MUSIC_FOLDER,
+    ):
+        _ensure_dir(directory)
+
+    # (target path, template shipped next to this file, empty fallback)
+    _seed_file(SETTINGS_FILE, "settings.json", "{}")
+    _seed_file(SYSTEM_GPT_SETTINGS, "system_gpt_settings.json", "{}")
+    _seed_file(MEMORY_FIVE_SIARA, "pamiec.json", "[]")
+    _seed_file(MEMORY_FIVE_MUZYKA, "pamiec_muzyki.json", "[]")
+    _seed_file(ACCIDENT_LOG, "accident_log.json", "[]")
+
+
+_ensure_runtime_layout()
+
+
 # *=========================================== Defensive state loading
 def _load_json(path: str, fallback):
     """Load JSON from *path*, falling back gracefully on missing/corrupt files."""