resolve merge conflicts for PR #40

- Remove merge conflict markers from blockchain RPC router
- Resolve dev_heartbeat.py conflicts (keep security vulnerability checks)
- Fix claim-task.py conflicts (unify TTL handling with timedelta)
- Preserve all production setup improvements from both branches

scripts/claim-task.py

@@ -7,7 +7,7 @@ Now with TTL/lease: claims expire after 2 hours to prevent stale locks.
 import os
 import json
 import subprocess
-from datetime import datetime, timezone
+from datetime import datetime, timedelta
 
 REPO_DIR = '/opt/aitbc'
 STATE_FILE = '/opt/aitbc/.claim-state.json'
@@ -17,7 +17,7 @@ MY_AGENT = os.getenv('AGENT_NAME', 'aitbc1')
 ISSUE_LABELS = ['security', 'bug', 'feature', 'refactor', 'task']  # priority order
 BONUS_LABELS = ['good-first-task-for-agent']
 AVOID_LABELS = ['needs-design', 'blocked', 'needs-reproduction']
-CLAIM_TTL_SECONDS = 7200  # 2 hours lease
+CLAIM_TTL = timedelta(hours=2)  # Stale claim timeout
 
 def query_api(path, method='GET', data=None):
     url = f"{API_BASE}/{path}"
@@ -125,10 +125,9 @@ def create_work_branch(issue_number, title):
     return branch_name
 
 def main():
-    now = datetime.utcnow().replace(tzinfo=timezone.utc)
-    now_iso = now.isoformat()
+    now = datetime.utcnow()
     now_ts = now.timestamp()
-    print(f"[{now_iso}] Claim task cycle starting...")
+    print(f"[{now.isoformat()}Z] Claim task cycle starting...")
     
     state = load_state()
     current_claim = state.get('current_claim')
@@ -147,6 +146,28 @@ def main():
             save_state(state)
             current_claim = None
     
+    if current_claim:
+        claimed_at_str = state.get('claimed_at')
+        if claimed_at_str:
+            try:
+                # Convert 'Z' suffix to offset for fromisoformat
+                if claimed_at_str.endswith('Z'):
+                    claimed_at_str = claimed_at_str[:-1] + '+00:00'
+                claimed_at = datetime.fromisoformat(claimed_at_str)
+                age = now - claimed_at
+                if age > CLAIM_TTL:
+                    print(f"Claim for issue #{current_claim} is stale (age {age}). Releasing.")
+                    # Try to delete remote claim branch
+                    claim_branch = state.get('claim_branch', f'claim/{current_claim}')
+                    subprocess.run(['git', 'push', 'origin', '--delete', claim_branch], 
+                                   capture_output=True, cwd=REPO_DIR)
+                    # Clear state
+                    state = {'current_claim': None, 'claimed_at': None, 'work_branch': None}
+                    save_state(state)
+                    current_claim = None
+            except Exception as e:
+                print(f"Error checking claim age: {e}. Will attempt to proceed.")
+    
     if current_claim:
         print(f"Already working on issue #{current_claim} (branch {state.get('work_branch')})")
         return
@@ -177,19 +198,19 @@ def main():
         if claim_issue(num):
             assign_issue(num, MY_AGENT)
             work_branch = create_work_branch(num, title)
-            expires_at = now_ts + CLAIM_TTL_SECONDS
+            expires_at = now_ts + int(CLAIM_TTL.total_seconds())
             state.update({
                 'current_claim': num,
                 'claim_branch': claim_branch,
                 'work_branch': work_branch,
-                'claimed_at': now_iso,
+                'claimed_at': now.isoformat() + 'Z',
                 'expires_at': expires_at,
                 'issue_title': title,
                 'labels': labels
             })
             save_state(state)
-            print(f"✅ Claimed issue #{num}. Work branch: {work_branch} (expires {datetime.fromtimestamp(expires_at, tz=timezone.utc).isoformat()})")
-            add_comment(num, f"Agent `{MY_AGENT}` claiming this task with TTL {CLAIM_TTL_SECONDS/3600}h. (automated)")
+            print(f"✅ Claimed issue #{num}. Work branch: {work_branch} (expires {datetime.fromtimestamp(expires_at).isoformat()})")
+            add_comment(num, f"Agent `{MY_AGENT}` claiming this task with TTL {int(CLAIM_TTL.total_seconds())/3600}h. (automated)")
             return
         else:
             print(f"Claim failed for #{num} (push error). Trying next...")
@@ -220,7 +241,7 @@ def cleanup_global_stale_claims(now_ts=None):
         if ts_result.returncode == 0 and ts_result.stdout.strip():
             commit_ts = int(ts_result.stdout.strip())
             age = now_ts - commit_ts
-            if age > CLAIM_TTL_SECONDS:
+            if age > int(CLAIM_TTL.total_seconds()):
                 print(f"Expired claim branch: {branch} (age {age/3600:.1f}h). Deleting.")
                 cleanup_stale_claim(branch)
                 cleaned += 1