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>

bot.py

@@ -4,9 +4,21 @@
 # pylint: disable=too-many-lines
 """
 Module of a python bot named Conjurer - used to work on BDSM discord servers.
+
+Startup is defensive by design:
+
+* every cog is loaded independently - one broken/missing dependency disables
+  that cog only, never the whole bot,
+* cogs that need a sibling service (musician / librarian) are only enabled
+  after a positive health check; a watchdog keeps re-checking and enables them
+  the moment the service comes alive,
+* fatal misconfiguration (missing Discord token) exits loudly on stderr with a
+  clear message instead of dying silently into a log file.
 """
 import asyncio
 import logging
+import os
+import sys
 
 # *=========================================== Standard Library Imports
 import random
@@ -15,12 +27,26 @@ from logging import handlers
 
 # *==============Imported libraries
 import discord
+import requests
 from discord.ext import commands
 
 from communication_subroutine import comm_subroutine
-from constants import ENCODING, LOGFILE, TOKEN
+from constants import (
+    ENCODING,
+    FILE_SERVICE_ADDRESS,
+    GET_MP3,
+    LIBRARIAN_SERVICE_ADDRESS,
+    LOGFILE,
+    TOKEN,
+)
+
 logger = logging.getLogger("discord")
 logger.setLevel(logging.DEBUG)
+formatter = logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s")
+
+# File log (rotated). constants ensures the directory exists; this is belt and
+# braces for exotic overrides.
+os.makedirs(os.path.dirname(LOGFILE) or ".", exist_ok=True)
 handler = handlers.RotatingFileHandler(
     filename=LOGFILE,
     encoding=ENCODING,
@@ -28,10 +54,15 @@ handler = handlers.RotatingFileHandler(
     maxBytes=6 * 1024 * 1024,
     backupCount=6,
     )
-formatter = logging.Formatter("%(asctime)s - %(name)s - %(levelname)s - %(message)s")
 handler.setFormatter(formatter)
 logger.addHandler(handler)
 
+# Console log so `docker logs` / journalctl actually show what happened.
+console_handler = logging.StreamHandler()
+console_handler.setLevel(logging.INFO)
+console_handler.setFormatter(formatter)
+logger.addHandler(console_handler)
+
 # *=========================================== Initializations
 intents = discord.Intents.default()
 intents.message_content = True
@@ -48,37 +79,129 @@ intents.moderation = True
 random.seed()
 client = commands.Bot(intents=intents, command_prefix="$")
 
+# *=========================================== Extension groups
+# Core cogs depend on nothing but the bot itself (broken ones are skipped
+# individually). Service groups are gated on a health check of the service
+# they talk to and enabled later by the watchdog when the service appears.
+CORE_EXTENSIONS = [
+    "administration_commands",
+    "ai_commands",
+    "other_commands",
+    "latex_commands",
+    "voice_recognition_commands",
+    "conanjurer_commands",
+]
+
+SERVICE_EXTENSION_GROUPS = {
+    # musician (file service): music download/search, radio control, file shares
+    "musician": {
+        "health_url": f"{FILE_SERVICE_ADDRESS}{GET_MP3}",
+        "extensions": ["music_commands", "radio_commands", "file_search_commands"],
+    },
+    # librarian: DOI / Crossref search
+    "librarian": {
+        "health_url": f"{LIBRARIAN_SERVICE_ADDRESS}/",
+        "extensions": ["librarian_commands"],
+    },
+}
+
+SERVICE_RECHECK_SECONDS = 300
+
+
+def _service_alive(url: str) -> bool:
+    """True when the service answers HTTP at all (any status code counts)."""
+    try:
+        requests.get(url, timeout=3)
+        return True
+    except requests.exceptions.RequestException:
+        return False
+
+
+async def _load_extension_safe(name: str) -> bool:
+    """Load one extension; log and continue instead of killing startup."""
+    if name in client.extensions:
+        return True
+    try:
+        await client.load_extension(name)
+        logger.info("Extension loaded: %s", name)
+        return True
+    except Exception:  # pylint: disable=broad-exception-caught
+        logger.exception("Extension FAILED (disabled, bot continues): %s", name)
+        return False
+
+
+async def _load_service_groups() -> bool:
+    """Health-check each service group and load its cogs when alive.
+
+    Returns True when anything new was loaded (caller may want to re-sync).
+    """
+    loaded_any = False
+    for service, group in SERVICE_EXTENSION_GROUPS.items():
+        missing = [e for e in group["extensions"] if e not in client.extensions]
+        if not missing:
+            continue
+        alive = await asyncio.to_thread(_service_alive, group["health_url"])
+        if not alive:
+            logger.warning(
+                "Service '%s' unreachable (%s) - cogs stay disabled: %s",
+                service,
+                group["health_url"],
+                ", ".join(missing),
+            )
+            continue
+        logger.info("Service '%s' is alive - enabling: %s", service, ", ".join(missing))
+        for extension in missing:
+            if await _load_extension_safe(extension):
+                loaded_any = True
+    return loaded_any
+
+
+async def _sync_tree() -> None:
+    try:
+        await client.tree.sync()
+    except Exception:  # pylint: disable=broad-exception-caught
+        logger.exception("Slash-command tree sync failed (commands may lag)")
+
+
+async def _service_watchdog() -> None:
+    """Periodically retry offline services and enable their cogs when up."""
+    while not client.is_closed():
+        await asyncio.sleep(SERVICE_RECHECK_SECONDS)
+        try:
+            if await _load_service_groups():
+                await _sync_tree()
+        except Exception:  # pylint: disable=broad-exception-caught
+            logger.exception("Service watchdog tick failed")
+
+
+_STARTUP_DONE = False
+
 
 # *=========================================== Define Events
 @client.event
 async def on_ready():
     """Metoda wywoływana przy połączeniu do serwera."""
-    logger = logging.getLogger("discord")
-    logger.debug("SAMPLE DEBUG LOG")
+    global _STARTUP_DONE  # pylint: disable=global-statement
     logger.info("%s has connected to Discord!", client.user)
-    # TODO: load vs reload
+    if _STARTUP_DONE:
+        logger.info("Reconnected - extensions already loaded")
+        return
+    _STARTUP_DONE = True
     logger.info("Reactor: online")
 
-    await client.load_extension("administration_commands")
+    for extension in CORE_EXTENSIONS:
+        await _load_extension_safe(extension)
 
-    await client.load_extension("librarian_commands")
-    await client.load_extension("music_commands")
-    await client.load_extension("radio_commands")
-
-    await client.load_extension("ai_commands")
-
-    await client.load_extension("other_commands")
-    await client.load_extension("voice_recognition_commands")
-    await client.load_extension("file_search_commands")
-    await client.load_extension("latex_commands")
-    await client.load_extension("conanjurer_commands")
+    await _load_service_groups()
     logger.info("Sensors: online")
 
     logger.info(client.cogs)
-    await client.tree.sync()
+    await _sync_tree()
     for com in client.commands:
         logger.info("Command %s is awejleble", com.qualified_name)
 
+    asyncio.create_task(_service_watchdog())
+
     logger.info("Logged in as ----> %s", client.user)
     logger.info("ID:%s ", client.user.id)
     logger.info("All systems: operational")
@@ -106,15 +229,10 @@ async def _run_bot(token: str, shutdown_event: asyncio.Event) -> None:
 
 
 async def main() -> None:
-    if not TOKEN:
-        logger.error("Discord token missing - set DISCORD_TOKEN or configure netrc")
-        return
-
     logger.info("Starting discord bot")
     shutdown_event = asyncio.Event()
     comm_stop_event = threading.Event()
 
-
     comm_task = asyncio.create_task(_run_comm_subroutine(comm_stop_event))
     bot_task = asyncio.create_task(_run_bot(TOKEN, shutdown_event))
 
@@ -133,4 +251,17 @@ async def main() -> None:
 
 # *================================== Run
 if __name__ == "__main__":
+    if not TOKEN:
+        # Loud, unmissable and in `docker logs`: this is THE most common cause
+        # of a silent container crash-loop.
+        MSG = (
+            "FATAL: Discord token missing.\n"
+            "Provide it via the DISCORD_TOKEN environment variable or a netrc "
+            "file (machine 'discord') at the path in CONJURER_NETRC_FILE.\n"
+            "Docker: check that your secrets mount exists, e.g.\n"
+            "  -v /srv/conjurer/secrets/.netrc:/secrets/.netrc:ro\n"
+            "  CONJURER_NETRC_FILE=/secrets/.netrc"
+        )
+        logger.critical(MSG)
+        sys.exit(MSG)
     asyncio.run(main())