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/actions.py

@@ -32,6 +32,10 @@ _MAX_TRIES = 5
 # Folder names to create when a target special-use folder is missing on the server.
 _DEFAULT_FOLDER_NAME = {"archive": "Archive", "trash": "Trash", "junk": "Spam"}
 
+# Moves into these folders record where the message came from (restore_mailbox_id)
+# so the Restore action can return it to its original folder.
+_REMOVAL_FOLDERS = frozenset({"archive", "trash", "junk"})
+
 
 def sanitize_flags(flags: Iterable[str]) -> frozenset[str]:
     return frozenset(f for f in flags if f in ALLOWED_FLAGS)
@@ -214,6 +218,9 @@ async def move_thread_to_folder_job(ctx: dict[str, Any], thread_id: str, special
             )
             message = await session.get(Message, mid)
             if message is not None and resolved is not None:
+                # Remember where it came from so Restore returns it there, not the Inbox.
+                if special_use in _REMOVAL_FOLDERS and message.mailbox_id != resolved:
+                    message.restore_mailbox_id = message.mailbox_id
                 message.mailbox_id = resolved
                 message.uid = new_uid
 
@@ -222,6 +229,74 @@ async def move_thread_to_folder_job(ctx: dict[str, Any], thread_id: str, special
     )
 
 
+async def restore_thread_job(ctx: dict[str, Any], thread_id: str) -> None:
+    """Move every message in a thread back to its original folder (Restore action).
+
+    Each message returns to ``restore_mailbox_id`` (the folder it was in before it
+    was archived/trashed) — e.g. a deleted Sent message goes back to Sent. Messages
+    with no recorded origin fall back to the account's Inbox.
+    """
+    tid = uuid.UUID(thread_id)
+    async with session_scope() as session:
+        messages = list(await session.scalars(select(Message).where(Message.thread_id == tid)))
+        if not messages:
+            return
+        user_id = messages[0].user_id
+        account_ids = list({m.account_id for m in messages})
+        accounts = {
+            a.id: a
+            for a in await session.scalars(select(Account).where(Account.id.in_(account_ids)))
+        }
+        mailboxes = list(
+            await session.scalars(select(Mailbox).where(Mailbox.account_id.in_(account_ids)))
+        )
+        path_by_id = {mb.id: mb.path for mb in mailboxes}
+        inbox_by_account = {
+            mb.account_id: mb.id for mb in mailboxes if mb.special_use == "inbox"
+        }
+        # (message_id, account_id, source_path, target_id) — resolve the target now.
+        plan: list[tuple[uuid.UUID, uuid.UUID, str, uuid.UUID, int]] = []
+        for m in messages:
+            target_id = m.restore_mailbox_id
+            if target_id is None or target_id not in path_by_id:
+                target_id = inbox_by_account.get(m.account_id)
+            if target_id is None or target_id == m.mailbox_id:
+                continue  # nowhere to restore to, or already there
+            plan.append(
+                (m.id, m.account_id, path_by_id.get(m.mailbox_id, "INBOX"), target_id, m.uid)
+            )
+
+    # (message_id, target_id, new_uid) applied after the network moves.
+    moves: list[tuple[uuid.UUID, uuid.UUID, int]] = []
+    for account_id in account_ids:
+        provider = build_provider(accounts[account_id])
+        try:
+            for mid, m_account, src_path, target_id, uid in plan:
+                if m_account != account_id:
+                    continue
+                target_path = path_by_id[target_id]
+                try:
+                    new_uid = await provider.move(uid, src_path, target_path)
+                except Exception:
+                    logger.exception("restore move failed for message %s -> %s", mid, target_path)
+                    continue
+                moves.append((mid, target_id, new_uid))
+        finally:
+            await provider.close()
+
+    async with session_scope() as session:
+        for mid, target_id, new_uid in moves:
+            message = await session.get(Message, mid)
+            if message is not None:
+                message.mailbox_id = target_id
+                message.uid = new_uid
+                message.restore_mailbox_id = None
+
+    await get_event_bus().publish(
+        "thread.updated", {"user_id": str(user_id), "thread_id": str(tid)}
+    )
+
+
 async def delete_thread_job(ctx: dict[str, Any], thread_id: str) -> None:
     """Permanently delete every message in a thread (server EXPUNGE + DB rows).