feat(telemetry): carry app_version on instance_started (#681)

app_version was attached only to feedback events; every other allowlist stripped it, so the install base could not be segmented by release. One property on the once-per-boot census event covers it. Fixes #674.

tests/unit/api/analytics-allowlist.test.ts

@@ -59,6 +59,7 @@ describe("sanitizeEventProperties", () => {
       os_platform: "linux",
       deploy_mode: "embedded",
       gpu_present: false,
+      app_version: "2.2.0",
       hostname: "leaked-hostname",
     });
     expect(out).toEqual({
@@ -66,6 +67,7 @@ describe("sanitizeEventProperties", () => {
       os_platform: "linux",
       deploy_mode: "embedded",
       gpu_present: false,
+      app_version: "2.2.0",
     });
     expect(out).not.toHaveProperty("hostname");
   });