Remove chain supervisor capability

Chains no longer spawn a supervisor task. Checkpoint contracts will be
automatically run as part of the DAG execution when dependencies complete.

- Remove supervisor task creation from start_chain handler
- Remove chain supervisor CLI commands
- Remove supervisor_task_id from StartChainResponse
- Remove withSupervisor option from frontend

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

2 files changed, 12 insertions, 47 deletions

diff --git a/makima/frontend/src/components/chains/ChainEditor.tsx b/makima/frontend/src/components/chains/ChainEditor.tsx
index 49e585c..d278607 100644
--- a/makima/frontend/src/components/chains/ChainEditor.tsx
+++ b/makima/frontend/src/components/chains/ChainEditor.tsx
@@ -54,7 +54,6 @@ export function ChainEditor({
   const [isStarting, setIsStarting] = useState(false);
   const [isStopping, setIsStopping] = useState(false);
   const [error, setError] = useState<string | null>(null);
-  const [withSupervisor, setWithSupervisor] = useState(false);
 
   // Load definitions when chain changes
   useEffect(() => {
@@ -174,14 +173,14 @@ export function ChainEditor({
     setIsStarting(true);
     setError(null);
     try {
-      await startChain(chain.id, { withSupervisor });
+      await startChain(chain.id);
       onRefresh();
     } catch (err) {
       setError(err instanceof Error ? err.message : "Failed to start chain");
     } finally {
       setIsStarting(false);
     }
-  }, [chain.id, onRefresh, withSupervisor]);
+  }, [chain.id, onRefresh]);
 
   const handleStopChain = useCallback(async () => {
     if (!confirm("Are you sure you want to stop this chain?")) return;
@@ -261,26 +260,13 @@ export function ChainEditor({
             </span>
             {/* Chain control buttons */}
             {chain.status === "pending" && definitions.length > 0 && (
-              <>
-                <label className="flex items-center gap-1 font-mono text-[10px] text-[#9bc3ff] cursor-pointer">
-                  <input
-                    type="checkbox"
-                    checked={withSupervisor}
-                    onChange={(e) => setWithSupervisor(e.target.checked)}
-                    className="w-3 h-3 accent-[#75aafc]"
-                  />
-                  <span title="Create a Claude supervisor task to monitor chain progress">
-                    Supervisor
-                  </span>
-                </label>
-                <button
-                  onClick={handleStartChain}
-                  disabled={isStarting}
-                  className="px-3 py-1 font-mono text-xs text-[#dbe7ff] bg-green-600 hover:bg-green-700 border border-green-500 transition-colors disabled:opacity-50"
-                >
-                  {isStarting ? "Starting..." : "Start Chain"}
-                </button>
-              </>
+              <button
+                onClick={handleStartChain}
+                disabled={isStarting}
+                className="px-3 py-1 font-mono text-xs text-[#dbe7ff] bg-green-600 hover:bg-green-700 border border-green-500 transition-colors disabled:opacity-50"
+              >
+                {isStarting ? "Starting..." : "Start Chain"}
+              </button>
             )}
             {chain.status === "active" && (
               <button
diff --git a/makima/frontend/src/lib/api.ts b/makima/frontend/src/lib/api.ts
index a08cba7..6a40aec 100644
--- a/makima/frontend/src/lib/api.ts
+++ b/makima/frontend/src/lib/api.ts
@@ -3323,7 +3323,6 @@ export interface UpdateContractDefinitionRequest {
 /** Response when starting a chain */
 export interface StartChainResponse {
   chainId: string;
-  supervisorTaskId: string | null;
   contractsCreated: string[];
   status: string;
 }
@@ -3422,30 +3421,10 @@ export async function getChainDefinitionGraph(
   return res.json();
 }
 
-/** Options for starting a chain */
-export interface StartChainOptions {
-  /** Whether to create a supervisor task that monitors chain progress */
-  withSupervisor?: boolean;
-  /** Repository URL for the supervisor task to work with */
-  repositoryUrl?: string;
-}
-
-/** Start a chain (creates root contracts and optionally spawns supervisor) */
-export async function startChain(
-  chainId: string,
-  options?: StartChainOptions
-): Promise<StartChainResponse> {
-  const body = options
-    ? JSON.stringify({
-        withSupervisor: options.withSupervisor ?? false,
-        repositoryUrl: options.repositoryUrl,
-      })
-    : undefined;
-
+/** Start a chain (creates root contracts based on DAG) */
+export async function startChain(chainId: string): Promise<StartChainResponse> {
   const res = await authFetch(`${API_BASE}/api/v1/chains/${chainId}/start`, {
     method: "POST",
-    headers: body ? { "Content-Type": "application/json" } : undefined,
-    body,
   });
   if (!res.ok) {
     const error = await res.json().catch(() => ({ message: res.statusText }));
@@ -3454,7 +3433,7 @@ export async function startChain(
   return res.json();
 }
 
-/** Stop a chain (kills supervisor, marks as archived) */
+/** Stop a chain (marks as archived) */
 export async function stopChain(chainId: string): Promise<{ stopped: boolean; status: string }> {
   const res = await authFetch(`${API_BASE}/api/v1/chains/${chainId}/stop`, {
     method: "POST",