fix(phase-35): prevent DuplicateObject on Alembic enum creation

Use create_type=False on sa.Enum column references inside
op.create_table so PostgreSQL does not attempt to CREATE TYPE
again after we already created them with checkfirst=True.

backend/alembic/versions/b020_add_jira_links_and_worklogs.py

@@ -19,7 +19,7 @@ depends_on: Union[str, Sequence[str], None] = None
 
 
 def upgrade() -> None:
-    # ── Enums ────────────────────────────────────────────────────────
+    # ── Enums — create once, then reference with create_type=False ───
     jira_link_entity_type = sa.Enum(
         "test", "technique", "campaign", "evidence",
         name="jiralinkentitytype",
@@ -31,11 +31,24 @@ def upgrade() -> None:
     jira_link_entity_type.create(op.get_bind(), checkfirst=True)
     jira_sync_direction.create(op.get_bind(), checkfirst=True)
 
+    # Re-reference with create_type=False so create_table won't try to
+    # CREATE TYPE again (which causes DuplicateObject on PostgreSQL).
+    entity_type_col = sa.Enum(
+        "test", "technique", "campaign", "evidence",
+        name="jiralinkentitytype",
+        create_type=False,
+    )
+    sync_dir_col = sa.Enum(
+        "aegis_to_jira", "jira_to_aegis", "bidirectional",
+        name="jirasyncdirection",
+        create_type=False,
+    )
+
     # ── jira_links table ─────────────────────────────────────────────
     op.create_table(
         "jira_links",
         sa.Column("id", postgresql.UUID(as_uuid=True), primary_key=True),
-        sa.Column("entity_type", jira_link_entity_type, nullable=False),
+        sa.Column("entity_type", entity_type_col, nullable=False),
         sa.Column("entity_id", postgresql.UUID(as_uuid=True), nullable=False),
         sa.Column("jira_issue_key", sa.String(50), nullable=False),
         sa.Column("jira_issue_id", sa.String(50)),
@@ -44,7 +57,7 @@ def upgrade() -> None:
         sa.Column("jira_priority", sa.String(50)),
         sa.Column("jira_assignee", sa.String(255)),
         sa.Column("jira_story_points", sa.String(10)),
-        sa.Column("sync_direction", jira_sync_direction, server_default="bidirectional"),
+        sa.Column("sync_direction", sync_dir_col, server_default="bidirectional"),
         sa.Column("last_synced_at", sa.DateTime),
         sa.Column("sync_metadata", postgresql.JSONB, server_default="{}"),
         sa.Column("created_by", postgresql.UUID(as_uuid=True), sa.ForeignKey("users.id")),