fix: stop command uses activeSessionId instead of renderer-only getActiveCascadeId #task-411

extension/src/command-handler.ts

@@ -25,6 +25,8 @@ export interface CommandHandlerContext {
     onAutoApproveChanged: (enabled: boolean) => void;
     /** Track recently sent Discord→AG texts to avoid echo relay */
     recentDiscordSentTexts: Map<string, number>;
+    /** Get the active cascade/session ID from step-probe polling state */
+    getActiveSessionId: () => string;
 }
 
 // ─── File-based command watcher ───
@@ -127,10 +129,12 @@ export function handleWSCommand(ctx: CommandHandlerContext, data: { text?: strin
  * This is the same mechanism AG's native red ■ stop button uses.
  */
 async function _cancelCurrentCascade(ctx: CommandHandlerContext) {
-    // 1. Get the active cascade ID from SDK titles manager
-    const cascadeId = ctx.sdk?.titles?.getActiveCascadeId?.();
+    // 1. Get the active cascade ID from extension state (step-probe polling)
+    //    NOTE: ctx.sdk.titles.getActiveCascadeId() is renderer-only (DOM scraping)
+    //    and always returns undefined from extension host. Use activeSessionId instead.
+    const cascadeId = ctx.getActiveSessionId();
     if (!cascadeId) {
-        ctx.logToFile('[STOP] No active cascade to cancel (getActiveCascadeId returned null)');
+        ctx.logToFile('[STOP] No active cascade — no session tracked yet');
         return;
     }