Merge gitea/main into the Motion branch

Motion was written against a base five commits behind main, so the
integration is the interesting part of this commit:

- The migration is renumbered 0014 -> 0015. Main shipped
  0014_piggy_conversations, and two migrations sharing an index is a
  journal that applies one of them.
- The seed-idempotency gate keeps main's all-tables diff rather than the
  motion_templates counter this branch added; the general check subsumes
  the specific one.
- Nav gains a Motion group alongside main's new Workspace group, and
  Piggy keeps the mark main gave it.
- Stat keeps main's container-scaled figure, which already carries the
  min-w-0 this branch added for the same reason.
- Piggy's page labels keep main's refusal wording for the four pages with
  no tool of their own, and gain the three Motion routes.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

packages/db/src/schema/motion.ts

@@ -47,7 +47,7 @@
  *
  * The FK cycle between `motion_templates.origin_artifact_id` and
  * `engagement_artifacts.template_id` is intentional — it is the loop — and it
- * is why migration `0014_motion.sql` is hand-written, adding one of the two
+ * is why migration `0015_motion.sql` is hand-written, adding one of the two
  * constraints in a separate `ALTER TABLE` after both tables exist.
  */
 import { sql } from 'drizzle-orm';