Enforce profile completeness in CreateDiscussion backend

The frontend gate alone is bypassable via gRPC. Mirror the existing
pattern (CreateEvent/SendMessage/etc.) and abort CreateDiscussion with
FAILED_PRECONDITION for incomplete profiles, with a regression test.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: kevinortiz43

app/backend/src/couchers/i18n/locales/en.json

@@ -95,6 +95,7 @@
     "host_request_too_short2_one": "Host request cannot be shorter than {{count}} character.",
     "host_request_too_short2_other": "Host request cannot be shorter than {{count}} characters.",
     "hosting_status_required": "Hosting status is required.",
+    "incomplete_profile_create_discussion": "You have to complete your profile before you can start a discussion.",
     "incomplete_profile_create_event": "You have to complete your profile before you can create an event.",
     "incomplete_profile_create_public_trip": "You have to complete your profile before you can create a public trip.",
     "incomplete_profile_send_friend_request": "You have to complete your profile before you can send a friend request.",

app/backend/src/couchers/servicers/discussions.py

@@ -8,6 +8,7 @@
 from couchers.context import CouchersContext, make_notification_user_context
 from couchers.db import can_moderate_node, session_scope
 from couchers.event_log import log_event
+from couchers.helpers.completed_profile import has_completed_profile
 from couchers.jobs.enqueue import queue_job
 from couchers.models import Cluster, ClusterSubscription, Discussion, ModerationObjectType, Thread, User
 from couchers.models.discussions import ContentChangeType, DiscussionVersion
@@ -119,6 +120,10 @@ def CreateDiscussion(
         if not cluster.small_community_features_enabled:
             context.abort_with_error_code(grpc.StatusCode.FAILED_PRECONDITION, "cannot_create_discussion")
 
+        user = session.execute(select(User).where(User.id == context.user_id)).scalar_one()
+        if not has_completed_profile(session, user):
+            context.abort_with_error_code(grpc.StatusCode.FAILED_PRECONDITION, "incomplete_profile_create_discussion")
+
         thread = Thread()
         session.add(thread)
         session.flush()

app/backend/src/tests/test_discussions.py

@@ -861,3 +861,23 @@ def test_admin_delete_discussion_creates_version_record(db):
         assert v.old_title == "Admin will delete this"
         assert v.new_title is None
         assert v.editor_user_id == admin.id
+
+
+def test_create_discussion_incomplete_profile(db):
+    user, token = generate_user(complete_profile=False)
+    user2, token2 = generate_user()
+
+    with session_scope() as session:
+        community_id = create_community(session, 0, 1, "Testing Community", [user2], [], None).id
+
+    with discussions_session(token) as api:
+        with pytest.raises(grpc.RpcError) as e:
+            api.CreateDiscussion(
+                discussions_pb2.CreateDiscussionReq(
+                    title="dummy title",
+                    content="dummy content",
+                    owner_community_id=community_id,
+                )
+            )
+        assert e.value.code() == grpc.StatusCode.FAILED_PRECONDITION
+        assert e.value.details() == "You have to complete your profile before you can start a discussion."