fix: agents self-assign unassigned issues for max throughput

Workers now pick ANY open issue (assigned to them OR unassigned) and
self-assign via Gitea API before starting work. No more empty queues.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

bin/gemini-loop.sh

@@ -149,7 +149,8 @@ all_issues.sort(key=priority)
 
 for i in all_issues:
     assignees = [a['login'] for a in (i.get('assignees') or [])]
-    if 'gemini' not in assignees:
+    # Take issues assigned to gemini OR unassigned (self-assign)
+    if assignees and 'gemini' not in assignees:
         continue
 
     title = i['title'].lower()
@@ -168,6 +169,18 @@ for i in all_issues:
 
     repo = i['_repo']
     owner, name = repo.split('/')
+
+    # Self-assign if unassigned
+    if not assignees:
+        try:
+            data = json.dumps({'assignees': ['gemini']}).encode()
+            req2 = urllib.request.Request(
+                f'{base}/api/v1/repos/{repo}/issues/{i["number"]}',
+                data=data, method='PATCH',
+                headers={'Authorization': f'token {token}', 'Content-Type': 'application/json'})
+            urllib.request.urlopen(req2, timeout=5)
+        except: pass
+
     print(json.dumps({
         'number': i['number'],
         'title': i['title'],