fix: restore API response formats + ai-ui-control ws + profile fields

- Restore {plugins: [...], total: N} for /plugins and /plugins/active-manifests
  (flat array broke frontend PluginRegistry → no menu items → empty UI)
- Restore {count: N} for /notifications/unread-count
  (scalar broke frontend notification badge)
- Fix ai_ui_control: on_install → on_activate for WS manager registration
  (WS 403 on every reconnect after container restart)
- Fix double /api/v1 prefix in useAIContext.ts and SuggestionBadge.tsx
- Add first_name, last_name, avatar_url to User model + migration 0032
- Extend UserUpdate schema with profile + password change fields
- Extend user_service.update_user with profile fields + password change
- Extend frontend UserResponse/UserUpdate types

alembic/versions/0032_user_profile_fields.py

@@ -0,0 +1,25 @@
+"""Add first_name, last_name, avatar_url to users table.
+
+Revision ID: 0032
+Revises: 0031
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+revision = "0032"
+down_revision = "0031"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column("users", sa.Column("first_name", sa.String(100), nullable=True))
+    op.add_column("users", sa.Column("last_name", sa.String(100), nullable=True))
+    op.add_column("users", sa.Column("avatar_url", sa.String(500), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("users", "avatar_url")
+    op.drop_column("users", "last_name")
+    op.drop_column("users", "first_name")