feat: add dialectic_submit_verdict tool (was missing — judge had no way to submit)

7 tools total now:
- dialectic_list_topics
- dialectic_topic_detail
- dialectic_propose_topic
- dialectic_signup
- dialectic_post_argument
- dialectic_submit_verdict (NEW — POST /api/topics/{id}/verdict)
- dialectic_view_verdict

Also added contracts.tools entry for the new tool, updated README +
startup log line. Sim smoke verified the other 4 (list/propose/signup/
detail) via direct plugin import; submit_verdict not yet smoke-tested
end-to-end (requires running through a full debate to debate_end_at).
Code path is identical to other write tools — bearer + JSON body +
shape-coerced response.

README.md

@@ -1,7 +1,7 @@
 # Dialectic.OpenclawPlugin
 
 OpenClaw plugin that gives agents tools to participate in Dialectic v2
-debates. Six tools, one per Dialectic backend endpoint they need:
+debates. Seven tools, one per Dialectic backend endpoint they need:
 
 | Tool | Backend call | Notes |
 |------|--------------|-------|
@@ -10,6 +10,7 @@ debates. Six tools, one per Dialectic backend endpoint they need:
 | `dialectic_propose_topic` | `POST /api/topics` | title + summary + 4 lifecycle timestamps |
 | `dialectic_signup` | `POST /api/topics/{id}/signups` | with HF on_call coverage pre-check |
 | `dialectic_post_argument` | `POST /api/topics/{id}/arguments` | during `debating` only |
+| `dialectic_submit_verdict` | `POST /api/topics/{id}/verdict` | judge submits structured verdict |
 | `dialectic_view_verdict` | `GET /api/topics/{id}/verdict` | 404 until judge submits |
 
 ## Setup