fix: isLockProcessAlive should return true for own PID (#2642)

The self-PID guard in isLockProcessAlive returned false for
process.pid, treating the current process as dead. This caused the
doctor to delete auto.lock and .gsd.lock/ during live auto-mode
sessions (via postUnitPreVerification), breaking the session lock
and silently stopping auto-mode.

The guard was originally added for startAuto() where a matching PID
could mean a recycled PID from a prior crash. But startAuto already
has its own `crashLock.pid !== process.pid` check before calling
isLockProcessAlive, so the function-level guard was redundant there
and harmful everywhere else.

Change `pid === process.pid` to return true (alive) instead of false.

Closes #2470

src/resources/extensions/gsd/crash-recovery.ts

@@ -76,12 +76,16 @@ export function readCrashLock(basePath: string): LockData | null {
 /**
  * Check whether the process that wrote the lock is still running.
  * Uses `process.kill(pid, 0)` which sends no signal but checks liveness.
- * Returns false if the PID matches our own (recycled PID from a prior run).
+ * Returns true if the PID matches our own — we are the lock holder (#2470).
  */
 export function isLockProcessAlive(lock: LockData): boolean {
   const pid = lock.pid;
   if (!Number.isInteger(pid) || pid <= 0) return false;
-  if (pid === process.pid) return false;
+  // Our own PID means WE hold this lock — we are alive. (#2470)
+  // Callers that need to distinguish "our lock" from "someone else's lock"
+  // (e.g. startAuto checking for a prior crashed session with a recycled PID)
+  // already guard with `crashLock.pid !== process.pid` before calling us.
+  if (pid === process.pid) return true;
   try {
     process.kill(pid, 0);
     return true;

src/resources/extensions/gsd/tests/auto-lock-creation.test.ts

@@ -140,7 +140,7 @@ test("isLockProcessAlive returns false for dead PID", () => {
   assert.equal(isLockProcessAlive(lock), false, "dead PID should return false");
 });
 
-test("isLockProcessAlive returns false for own PID (recycled)", () => {
+test("#2470: isLockProcessAlive returns true for own PID (we hold the lock)", () => {
   const lock = {
     pid: process.pid,
     startedAt: new Date().toISOString(),
@@ -148,7 +148,7 @@ test("isLockProcessAlive returns false for own PID (recycled)", () => {
     unitId: "M001/S01/T01",
     unitStartedAt: new Date().toISOString(),
   };
-  assert.equal(isLockProcessAlive(lock), false, "own PID should return false (recycled)");
+  assert.equal(isLockProcessAlive(lock), true, "own PID means we are alive — not stale (#2470)");
 });
 
 test("isLockProcessAlive returns false for invalid PID", () => {

src/resources/extensions/gsd/tests/crash-recovery.test.ts

@@ -68,8 +68,10 @@ test("clearLock is safe when no lock exists", (t) => {
 
 // ─── isLockProcessAlive ──────────────────────────────────────────────────
 
-test("isLockProcessAlive returns true for current process (different pid)", () => {
-  // Our own PID is explicitly excluded (recycled PID guard)
+test("#2470: isLockProcessAlive returns true for own PID (we hold the lock)", () => {
+  // Own PID means we ARE the lock holder — alive, not stale. (#2470)
+  // Callers that need recycled-PID detection (e.g. startAuto) already
+  // guard with `crashLock.pid !== process.pid` before calling us.
   const lock: LockData = {
     pid: process.pid,
     startedAt: new Date().toISOString(),
@@ -77,7 +79,7 @@ test("isLockProcessAlive returns true for current process (different pid)", () =
     unitId: "M001/S01/T01",
     unitStartedAt: new Date().toISOString(),
   };
-  assert.equal(isLockProcessAlive(lock), false, "own PID should return false");
+  assert.equal(isLockProcessAlive(lock), true, "own PID should return true — we are alive");
 });
 
 test("isLockProcessAlive returns false for dead PID", () => {