feat(email): implement full email plugin

Supports Gmail (OAuth + filter API), Microsoft 365 (OAuth + full rule CRUD via
O365), ProtonMail (Bridge, paid only), and generic IMAP/SMTP providers.

16 tools: list_inbox, read, send, reply, forward, move, delete, mark_read,
search, list_folders, create_folder, inbox_summary, list_rules, create_rule,
delete_rule, bulk_action.

Background daemon task monitors inbox via IMAP IDLE and publishes new-email
events to daemon/events.py for messaging bot pickup. Setup wizard warns
explicitly about ProtonMail Bridge + paid plan requirement and recommends
a messaging bot if none is configured.

36 unit tests covering: HTML stripping, header decoding, raw message parsing,
IMAP search builder, Gmail/Outlook rule normalisation, folder-not-found path,
events bus, Bridge connectivity guard, and tool approval flags.

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

src/pyra/bundled_plugins/email/manifest.json

@@ -0,0 +1,12 @@
+{
+  "name": "email",
+  "version": "1.0.0",
+  "description": "Full email management — read, send, search, sort, and create filter rules. Supports Gmail, Microsoft 365, ProtonMail (Bridge), and any IMAP provider. Background monitoring pushes new-email summaries to your configured messaging bot.",
+  "author": "pyra",
+  "requires": [
+    "imap-tools>=1.7.0",
+    "google-api-python-client>=2.120.0",
+    "google-auth-oauthlib>=1.2.0",
+    "O365>=2.0.36"
+  ]
+}