stage-8: cron scheduler with APScheduler

Scheduler class, cron/jobs.json, Discord /cron commands, CLI cron subcommand, job lifecycle management. 88 new tests (281 total).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/main.py

@@ -9,7 +9,8 @@ from pathlib import Path
 
 from src.config import load_config
 from src.secrets import get_secret
-from src.adapters.discord_bot import create_bot
+from src.adapters.discord_bot import create_bot, split_message
+from src.scheduler import Scheduler
 
 PROJECT_ROOT = Path(__file__).resolve().parent.parent
 PID_FILE = PROJECT_ROOT / "echo-core.pid"
@@ -43,6 +44,26 @@ def main():
     config = load_config()
     client = create_bot(config)
 
+    # Scheduler setup
+    async def _send_to_channel(channel_alias: str, text: str) -> None:
+        """Callback: resolve alias and send text to Discord channel."""
+        channels = config.get("channels", {})
+        ch_info = channels.get(channel_alias)
+        if not ch_info:
+            logger.warning("Cron: unknown channel alias '%s'", channel_alias)
+            return
+        channel_id = ch_info.get("id")
+        channel = client.get_channel(int(channel_id))
+        if channel is None:
+            logger.warning("Cron: channel %s not found in Discord cache", channel_id)
+            return
+        chunks = split_message(text)
+        for chunk in chunks:
+            await channel.send(chunk)
+
+    scheduler = Scheduler(send_callback=_send_to_channel, config=config)
+    client.scheduler = scheduler  # type: ignore[attr-defined]
+
     # PID file
     PID_FILE.write_text(str(os.getpid()))
 
@@ -51,6 +72,7 @@ def main():
 
     def handle_signal(sig, frame):
         logger.info("Received signal %s, shutting down...", sig)
+        loop.create_task(scheduler.stop())
         loop.create_task(client.close())
 
     signal.signal(signal.SIGTERM, handle_signal)
@@ -59,6 +81,7 @@ def main():
     try:
         loop.run_until_complete(client.start(token))
     except KeyboardInterrupt:
+        loop.run_until_complete(scheduler.stop())
         loop.run_until_complete(client.close())
     finally:
         PID_FILE.unlink(missing_ok=True)