test: stabilize release CI fixtures

Author: jmagly

CHANGELOG.md

@@ -73,6 +73,10 @@ and this project uses [Calendar Versioning (CalVer)](https://calver.org/) with n
 - **Codex skill context budget** - Codex uses the canonical shared
   `.agents/skills/` projection and deployment conformance prevents duplicate
   skill surfaces from exhausting the context budget (#1884).
+- **Deterministic CI fixtures** - daemon HTTP tests now ask the operating
+  system for an available port, and Git-history peak-day fixtures use a fixed
+  timestamp so concurrent processes and UTC midnight cannot cause release-gate
+  failures.
 
 ### Security
 

test/unit/daemon/web-server.test.ts

@@ -76,14 +76,12 @@ describe('WebServer', () => {
   let supervisor;
   let baseUrl;
 
-  // Use a random high port to avoid conflicts
-  const getPort = () => 10000 + Math.floor(Math.random() * 50000);
-
   beforeEach(async () => {
     supervisor = new StubSupervisor();
-    const port = getPort();
     server = new WebServer({
-      port,
+      // Let the OS allocate an available ephemeral port. Choosing a random
+      // port still races with other processes between selection and listen.
+      port: 0,
       host: '127.0.0.1',
       daemonSupervisor: supervisor,
     });
@@ -200,9 +198,8 @@ describe('WebServer', () => {
     let authedUrl;
 
     beforeEach(async () => {
-      const port = getPort();
       authedServer = new WebServer({
-        port,
+        port: 0,
         host: '127.0.0.1',
         token: 'secret-token',
         daemonSupervisor: supervisor,
@@ -325,8 +322,7 @@ describe('WebServer', () => {
     let noSupServer;
 
     beforeEach(async () => {
-      const port = getPort();
-      noSupServer = new WebServer({ port, host: '127.0.0.1' });
+      noSupServer = new WebServer({ port: 0, host: '127.0.0.1' });
       await noSupServer.start();
     });
 

test/unit/intake/git-history-analyzer.test.ts

@@ -178,7 +178,9 @@ def456|Jane|jane@example.com|1700100000|Another commit`;
     });
 
     it('should identify peak day', () => {
-      const now = Math.floor(Date.now() / 1000);
+      // Keep the fixture away from a UTC day boundary. Using the live clock
+      // made the five one-minute-spaced commits straddle midnight in CI.
+      const now = Math.floor(Date.UTC(2026, 6, 15, 12, 0, 0) / 1000);
       const dayInSeconds = 24 * 60 * 60;
       const peakDate = new Date((now - dayInSeconds) * 1000).toISOString().split('T')[0];