feat(daemon): add async event bus for inter-plugin notifications

Adds daemon/events.py — a lightweight asyncio.Queue-based publish/subscribe
bus that lets daemon tasks communicate without direct imports between plugins.
Email plugin publishes new_email events; messaging bots consume via
subscribe_forever(). Also adds email optional-dependency group to pyproject.toml
(imap-tools, google-api-python-client, google-auth-oauthlib, O365).

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

pyproject.toml

@@ -35,6 +35,12 @@ gdrive    = ["google-api-python-client>=2.120.0", "google-auth-oauthlib>=1.2.0"]
 onedrive  = ["msal>=1.28.0"]
 dropbox   = ["dropbox>=12.0.0"]
 daemon    = ["aiofiles>=23.0.0"]
+email     = [
+    "imap-tools>=1.7.0",
+    "google-api-python-client>=2.120.0",
+    "google-auth-oauthlib>=1.2.0",
+    "O365>=2.0.36",
+]
 all-plugins = [
     "caldav>=1.3.0", "webdav4>=0.9.0", "vobject>=0.9.6",
     "matrix-nio>=0.24.0", "aiofiles>=23.0.0",
@@ -44,6 +50,8 @@ all-plugins = [
     "google-api-python-client>=2.120.0", "google-auth-oauthlib>=1.2.0",
     "msal>=1.28.0",
     "dropbox>=12.0.0",
+    "imap-tools>=1.7.0",
+    "O365>=2.0.36",
 ]
 
 [project.scripts]

src/pyra/daemon/__init__.py

@@ -1,6 +1,7 @@
 """Pyra background daemon package."""
 
 from pyra.daemon.core import PluginSupervisor, run_foreground, start_background
+from pyra.daemon.events import publish, subscribe_forever
 from pyra.daemon.ipc import IpcClient, IpcServer, send_command
 from pyra.daemon.pid import PidFile, PidFileError, resolve_pid_path
 from pyra.daemon.service import detect_platform, install_service, uninstall_service
@@ -9,6 +10,8 @@ __all__ = [
     "run_foreground",
     "start_background",
     "PluginSupervisor",
+    "publish",
+    "subscribe_forever",
     "IpcClient",
     "IpcServer",
     "send_command",

src/pyra/daemon/events.py

@@ -0,0 +1,46 @@
+"""Async notification bus for inter-plugin communication in the daemon.
+
+Plugins publish events to a shared asyncio.Queue; other plugins (e.g. messaging
+bots) consume them via subscribe_forever().  No direct plugin-to-plugin imports
+are needed — both sides just use this module.
+
+Event shape (by convention):
+    {"type": "new_email", "priority": int, "from": str, "subject": str,
+     "summary": str, "uid": str, "folder": str}
+    {"type": "new_message", "bot": str, "user_id": str, "text": str}
+"""
+from __future__ import annotations
+
+import asyncio
+from typing import Any, AsyncGenerator
+
+_queue: asyncio.Queue[dict[str, Any]] | None = None
+
+
+def get_queue() -> asyncio.Queue[dict[str, Any]]:
+    global _queue
+    if _queue is None:
+        _queue = asyncio.Queue(maxsize=200)
+    return _queue
+
+
+async def publish(event: dict[str, Any]) -> None:
+    """Emit an event. Drops silently if the queue is full (daemon is overloaded)."""
+    q = get_queue()
+    try:
+        q.put_nowait(event)
+    except asyncio.QueueFull:
+        pass
+
+
+async def subscribe_forever() -> AsyncGenerator[dict[str, Any], None]:
+    """Async generator — yields events as they arrive. Intended for daemon tasks."""
+    q = get_queue()
+    while True:
+        yield await q.get()
+
+
+def reset() -> None:
+    """Discard the current queue and create a fresh one. FOR TESTS ONLY."""
+    global _queue
+    _queue = None