fix: idle watchdog false-fires on active agents (#52) (#65)

The idle watchdog checked lastProgressAt to detect stalled agents, but
nothing updated that timestamp during normal execution. Any task taking
>10min triggered false idle recovery, steering messages, and eventually
got skipped — even while actively writing code.

Add detectWorkingTreeActivity() check before recovery: if git reports
uncommitted changes, the agent is working. Bump lastProgressAt and
skip recovery. Genuinely idle agents (clean working tree) still get
recovered as before.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

src/resources/extensions/gsd/auto.ts

@@ -36,7 +36,6 @@ import {
   clearUnitRuntimeRecord,
   formatExecuteTaskRecoveryStatus,
   inspectExecuteTaskDurability,
-  recordUnitProgress,
   readUnitRuntimeRecord,
   writeUnitRuntimeRecord,
 } from "./unit-runtime.js";
@@ -985,6 +984,17 @@ async function dispatchNextUnit(
     if (!runtime) return;
     if (Date.now() - runtime.lastProgressAt < idleTimeoutMs) return;
 
+    // Before triggering recovery, check if the agent is actually producing
+    // work on disk.  `git status --porcelain` is cheap and catches any
+    // staged/unstaged/untracked changes the agent made since lastProgressAt.
+    if (detectWorkingTreeActivity(basePath)) {
+      writeUnitRuntimeRecord(basePath, unitType, unitId, currentUnit.startedAt, {
+        lastProgressAt: Date.now(),
+        lastProgressKind: "filesystem-activity",
+      });
+      return;
+    }
+
     if (currentUnit) {
       const modelId = ctx.model?.id ?? "unknown";
       snapshotUnitMetrics(ctx, currentUnit.type, currentUnit.id, currentUnit.startedAt, modelId);
@@ -2136,6 +2146,25 @@ export function skipExecuteTask(
   return true;
 }
 
+/**
+ * Detect whether the agent is producing work on disk by checking git for
+ * any working-tree changes (staged, unstaged, or untracked). Returns true
+ * if there are uncommitted changes — meaning the agent is actively working,
+ * even though it hasn't signaled progress through runtime records.
+ */
+function detectWorkingTreeActivity(cwd: string): boolean {
+  try {
+    const out = execSync("git status --porcelain", {
+      cwd,
+      stdio: ["pipe", "pipe", "pipe"],
+      timeout: 5000,
+    });
+    return out.toString().trim().length > 0;
+  } catch {
+    return false;
+  }
+}
+
 /**
  * Resolve the expected artifact for a non-execute-task unit to an absolute path.
  * Returns null for unit types that don't produce a single file (execute-task,