mail UX: restore-to-folder, draft/attachment fixes, printing, sidebar collapse

Backend:
- Restore returns each message to its original folder (e.g. Sent/Archive) instead
  of always the Inbox: new messages.restore_mailbox_id (migration 0010) +
  restore_thread_job.
- Drafts: expunge reconciliation for the Drafts poll (provider.list_uids /
  _reconcile_drafts) clears phantom "remote" drafts; send + discard drop the
  mirrored DB row; adopting a remote draft carries its real attachments into the
  compose flow.
- Thread detail/list are folder-aware: individually trashed/spam messages are
  hidden outside their folder, Trash/Spam show only their own messages, and the
  mail-list message count matches the view.

Frontend:
- Thread reading panel: fix newest-first card overlap/spacing (expand-all and
  single expand), hide Reply/Forward on trashed messages, close the Actions menu
  on message-body (iframe) clicks, scroll to the inline composer, and prompt
  Save draft / Discard on the X close.
- Composer: remount when switching drafts, dirty-tracking to stop duplicate IMAP
  mirrors, and close the From/More dropdowns on outside click.
- Sidebar: collapse/expand toggle (icons-only ~60px rail) and a log-out icon on
  Sign out.
- Mail-standard printing in a new window with reliable page margins (lib/print.ts).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01U72FZiF1W1pb8XxyWBTREA

backend/app/sync/engine.py

@@ -15,7 +15,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.config import get_settings
 from app.events import get_event_bus
 from app.indexer.indexer import PersistResult, persist_message
-from app.models import Account, Mailbox, Message
+from app.models import Account, Draft, Mailbox, Message
 from app.providers.base import MailboxDelta, ProviderNotSupported
 from app.providers.imap_smtp import ImapSmtpProvider
 from app.search.factory import get_search_backend
@@ -248,6 +248,49 @@ async def apply_delta(
             },
         )
 
+    # Expunge reconciliation for Drafts. The mirror mechanism (and other clients)
+    # expunge server copies, but a CONDSTORE poll doesn't report vanished UIDs, so
+    # expunged drafts would linger in the DB and resurface as phantom "remote"
+    # drafts. Drafts folders are small, so a full UID reconcile per poll is cheap.
+    if mailbox.special_use == "drafts":
+        await _reconcile_drafts(provider, account, mailbox)
+
+
+async def _reconcile_drafts(
+    provider: ImapSmtpProvider, account: Account, mailbox: Mailbox
+) -> None:
+    """Drop DB rows for drafts that no longer exist on the server (were expunged)."""
+    from app.db import session_scope
+
+    try:
+        server_uids = await provider.list_uids(mailbox.path)
+    except Exception:
+        logger.exception("drafts reconcile: list_uids failed for %s", mailbox.path)
+        return
+
+    async with session_scope() as session:
+        db_uids = set(
+            await session.scalars(select(Message.uid).where(Message.mailbox_id == mailbox.id))
+        )
+        gone = db_uids - server_uids
+        if not gone:
+            return
+        await session.execute(
+            delete(Message).where(Message.mailbox_id == mailbox.id, Message.uid.in_(gone))
+        )
+        # A local draft whose mirrored copy vanished becomes local-only again.
+        await session.execute(
+            update(Draft)
+            .where(Draft.account_id == account.id, Draft.imap_uid.in_(gone))
+            .values(imap_uid=None)
+        )
+
+    logger.info("drafts reconcile: removed %d expunged row(s) in %s", len(gone), mailbox.path)
+    await get_event_bus().publish(
+        "message.deleted",
+        {"user_id": str(account.user_id), "account_id": str(account.id), "mailbox": mailbox.path},
+    )
+
 
 async def live_loop(
     account_id: uuid.UUID, mailbox_path: str = "INBOX", stop: asyncio.Event | None = None