feat(pi): record session-start make test in test-balls via event bus

Emit test-balls:record on the shared pi.events bus after the session-start
make test run completes, so test-balls shows a ball for it like any other run.

The run is now fire-and-forget: session start no longer blocks on make test,
and the emit always lands after every extension's session_start handler has
run (project extensions load before global ones, so emitting synchronously
raced test-balls' runs reset). Exactly one ball is recorded per run, even if
UI reporting fails.

.pi/extensions/run_make_test.ts

@@ -1,9 +1,29 @@
-import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
+import type { ExtensionAPI, ExtensionContext } from "@earendil-works/pi-coding-agent";
 
 export default function (pi: ExtensionAPI) {
   pi.on("session_start", async (_event, ctx) => {
+    // Fire-and-forget: do not block session start on the test run, and let the
+    // "test-balls:record" event land after every extension's session_start handler
+    // has run (project extensions load before global ones, so emitting synchronously
+    // from this handler would race test-balls' runs reset).
+    void runMakeTest(pi, ctx).catch((error) => {
+      console.error("run_make_test:", error);
+    });
+  });
+}
+
+async function runMakeTest(pi: ExtensionAPI, ctx: ExtensionContext): Promise<void> {
+  // Record exactly one ball per run, even if UI reporting below fails.
+  let recorded = false;
+  const record = (pass: boolean) => {
+    if (recorded) return;
+    recorded = true;
+    pi.events.emit("test-balls:record", { pass, command: "make test", ts: Date.now() });
+  };
+
   try {
     const { stdout, stderr, code } = await pi.exec("make", ["test"]);
+    record(code === 0);
     const output = stdout + stderr;
 
     if (code === 0) {
@@ -24,6 +44,7 @@ export default function (pi: ExtensionAPI) {
       display: true,
     }, { deliverAs: "followUp" });
   } catch (error) {
+    record(false);
     const message = error instanceof Error ? error.message : String(error);
     pi.sendMessage({
       customType: "run-make-test",
@@ -33,5 +54,4 @@ export default function (pi: ExtensionAPI) {
       display: true,
     }, { deliverAs: "followUp" });
   }
-  });
 }