sync-v2 step 1: worker roles + interactive/bulk queue split

- config: WORKER_ROLE (sync|jobs|all), INTERACTIVE_CONCURRENCY, BULK_CONCURRENCY.
- queue: named queues (interactive/bulk) + enqueue_job() router; sync_bootstrap
  goes to bulk, all other jobs to interactive.
- workers.run: single entrypoint; role=jobs runs both arq consumers (per-queue
  timeout/concurrency), role=sync runs the supervisor, all=both (dev default).
- docker-compose: worker-sync + worker-jobs services (shared image, nofile
  ulimit); backend/Dockerfile; Makefile worker/worker-sync/worker-jobs targets.
- tests repointed to app.queue.get_arq_pool; supervisor behavior unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/app/api/compose.py

@@ -25,7 +25,7 @@ from app.outbox.schemas import (
     SendResponse,
 )
 from app.outbox.service import DraftError, cancel_outbox, create_outbox, upsert_draft
-from app.queue import get_arq_pool
+from app.queue import enqueue_job
 
 router = APIRouter(tags=["compose"], dependencies=[Depends(require_csrf)])
 
@@ -155,9 +155,7 @@ async def list_remote_drafts(user: CurrentUser, db: DbSession) -> list[RemoteDra
 
 
 @router.post("/drafts/adopt/{message_id}", response_model=DraftOut)
-async def adopt_remote_draft(
-    message_id: uuid.UUID, user: CurrentUser, db: DbSession
-) -> DraftOut:
+async def adopt_remote_draft(message_id: uuid.UUID, user: CurrentUser, db: DbSession) -> DraftOut:
     """Turn a Drafts-folder message into an editable local draft (linked by UID)."""
     msg = await db.scalar(
         select(Message)
@@ -235,8 +233,7 @@ async def publish_draft(draft_id: uuid.UUID, user: CurrentUser, db: DbSession) -
     draft = await db.scalar(select(Draft).where(Draft.id == draft_id, Draft.user_id == user.id))
     if draft is None:
         raise_api_error(404, "not_found", "draft not found")
-    pool = await get_arq_pool()
-    await pool.enqueue_job("push_draft_to_imap_job", str(draft_id))
+    await enqueue_job("push_draft_to_imap_job", str(draft_id))
     return {"status": "queued"}
 
 
@@ -250,8 +247,7 @@ async def delete_draft(draft_id: uuid.UUID, user: CurrentUser, db: DbSession) ->
     await db.commit()
     # Remove the mirrored copy from the server Drafts folder too.
     if imap_uid:
-        pool = await get_arq_pool()
-        await pool.enqueue_job("remove_imap_draft_job", str(account_id), imap_uid)
+        await enqueue_job("remove_imap_draft_job", str(account_id), imap_uid)
     return {"status": "deleted"}
 
 
@@ -265,8 +261,7 @@ async def send(body: SendRequest, user: CurrentUser, db: DbSession) -> SendRespo
     outbox = await create_outbox(db, user_id=user.id, draft=draft)
     await db.commit()
 
-    pool = await get_arq_pool()
-    await pool.enqueue_job(
+    await enqueue_job(
         "send_job",
         str(outbox.id),
         _defer_by=timedelta(seconds=get_settings().undo_seconds),