fix(selfhost): wire or remove the dead gittensory_jobs_deferred_total metric

src/server.ts

@@ -525,7 +525,6 @@ async function main(): Promise<void> {
     "gittensory_jobs_dead_total",
     "gittensory_jobs_rate_limited_total",
     "gittensory_jobs_rate_limit_deferred_total",
-    "gittensory_jobs_deferred_total",
     "gittensory_jobs_coalesced_total",
     "gittensory_jobs_recovered_total",
   ]) {

test/unit/server-persisted-job-metrics.test.ts

@@ -0,0 +1,33 @@
+import { readFileSync } from "node:fs";
+import { describe, expect, it } from "vitest";
+
+const read = (path: string) => readFileSync(path, "utf8");
+
+// Regression for #2508: gittensory_jobs_deferred_total was registered as a persisted gauge in server.ts
+// but no queue driver ever called recordQueueMetric with that name -- dead instrumentation that always
+// reported 0. Pin the invariant the fix establishes: every metric name in server.ts's persisted-gauge list
+// must have a real recordQueueMetric call site in BOTH queue drivers, so a future dead entry can't sneak
+// back in the same way. Source-text assertions, not a runtime harness: server.ts has no test harness
+// (it's Codecov-ignored) and this is a static wiring invariant, not runtime behavior.
+describe("server.ts persisted job-queue metrics (#2508)", () => {
+  it("registers only metric names both sqlite-queue.ts and pg-queue.ts actually record", () => {
+    const server = read("src/server.ts");
+    const sqliteQueue = read("src/selfhost/sqlite-queue.ts");
+    const pgQueue = read("src/selfhost/pg-queue.ts");
+
+    const listMatch = server.match(
+      /const durableJobMetric[\s\S]*?for \(const name of \[([\s\S]*?)\]\) \{/,
+    );
+    expect(listMatch, "persisted-gauge metric list not found in server.ts").not.toBeNull();
+    const registered = [...listMatch![1]!.matchAll(/"([a-z_]+)"/g)].map((m) => m[1]!);
+    expect(registered.length).toBeGreaterThan(0);
+
+    for (const name of registered) {
+      const callSite = `recordQueueMetric(driver, "${name}"`;
+      expect(sqliteQueue.includes(callSite), `sqlite-queue.ts never calls recordQueueMetric for "${name}"`).toBe(true);
+      expect(pgQueue.includes(`recordQueueMetric("${name}"`), `pg-queue.ts never calls recordQueueMetric for "${name}"`).toBe(true);
+    }
+
+    expect(registered).not.toContain("gittensory_jobs_deferred_total");
+  });
+});