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/api/compose.py

@@ -16,7 +16,7 @@ from app.config import get_settings
 from app.db import get_session
 from app.identity.deps import CurrentUser, require_csrf
 from app.indexer import blobstore
-from app.models import BodyPart, ComposeAttachment, Draft, Mailbox, Message
+from app.models import Attachment, BodyPart, ComposeAttachment, Draft, Mailbox, Message
 from app.outbox.schemas import (
     DraftIn,
     DraftOut,
@@ -24,7 +24,13 @@ from app.outbox.schemas import (
     SendRequest,
     SendResponse,
 )
-from app.outbox.service import DraftError, cancel_outbox, create_outbox, upsert_draft
+from app.outbox.service import (
+    DraftError,
+    cancel_outbox,
+    create_outbox,
+    delete_mirrored_draft_row,
+    upsert_draft,
+)
 from app.queue import enqueue_job
 
 router = APIRouter(tags=["compose"], dependencies=[Depends(require_csrf)])
@@ -183,6 +189,30 @@ async def adopt_remote_draft(message_id: uuid.UUID, user: CurrentUser, db: DbSes
     parts = list(await db.scalars(select(BodyPart).where(BodyPart.message_id == msg.id)))
     html = next((p.content for p in parts if p.kind == "html_sanitized"), "")
     text = next((p.content for p in parts if p.kind == "text"), "")
+
+    # Carry the draft's real (non-inline) attachments over as compose attachments,
+    # so they show in the editor and are re-attached on save/send. The underlying
+    # blobs are shared by sha256 — we only add new ComposeAttachment references.
+    att_rows = list(
+        await db.scalars(
+            select(Attachment)
+            .where(Attachment.message_id == msg.id, Attachment.content_id.is_(None))
+            .order_by(Attachment.filename)
+        )
+    )
+    attachment_ids: list[str] = []
+    for a in att_rows:
+        ca = ComposeAttachment(
+            user_id=user.id,
+            filename=a.filename,
+            mime_type=a.mime_type,
+            size_bytes=a.size_bytes,
+            blob_sha256=a.blob_sha256,
+        )
+        db.add(ca)
+        await db.flush()
+        attachment_ids.append(str(ca.id))
+
     payload = {
         "to": [_fmt_addr(a) for a in msg.to_addr],
         "cc": [_fmt_addr(a) for a in msg.cc_addr],
@@ -190,7 +220,7 @@ async def adopt_remote_draft(message_id: uuid.UUID, user: CurrentUser, db: DbSes
         "subject": msg.subject,
         "html": html,
         "text": text,
-        "attachment_ids": [],
+        "attachment_ids": attachment_ids,
     }
     draft = Draft(
         user_id=user.id,
@@ -244,6 +274,10 @@ async def delete_draft(draft_id: uuid.UUID, user: CurrentUser, db: DbSession) ->
         raise_api_error(404, "not_found", "draft not found")
     account_id, imap_uid = draft.account_id, draft.imap_uid
     await db.delete(draft)
+    # Drop the mirrored Drafts-folder message row now so the draft doesn't
+    # resurface as an "other client" remote draft after the local row is gone.
+    if imap_uid:
+        await delete_mirrored_draft_row(db, account_id=account_id, imap_uid=imap_uid)
     await db.commit()
     # Remove the mirrored copy from the server Drafts folder too.
     if imap_uid: