test(03-02): add failing tests for hook server integration and poll slowdown

- TestHookServerStartsWithDaemon, TestHookServerStopsWithDaemon
- TestHookServerPortBusy (graceful degradation)
- TestPollSlowdown (20s when hooks active, 5s otherwise)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

daemon_test.go

@@ -2,9 +2,13 @@ package main
 
 import (
 	"encoding/json"
+	"fmt"
+	"io"
 	"net"
+	"net/http"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 	"time"
 )
@@ -212,7 +216,128 @@ func newTestDaemon(t *testing.T) *Daemon {
 		t.Fatalf("labels: %v", err)
 	}
 
-	return NewDaemon(sockPath, procDir, claudeDir, labels)
+	d := NewDaemon(sockPath, procDir, claudeDir, labels)
+	d.hookPort = 0 // disable hook server by default in tests
+	return d
+}
+
+func TestHookServerStartsWithDaemon(t *testing.T) {
+	d := newTestDaemon(t)
+
+	// Assign a dynamic port for the hook server
+	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+	port := ln.Addr().(*net.TCPAddr).Port
+	ln.Close()
+
+	d.hookPort = port
+
+	if err := d.Start(); err != nil {
+		t.Fatalf("start: %v", err)
+	}
+	defer d.Stop()
+
+	// POST to /hook should return 200
+	url := fmt.Sprintf("http://127.0.0.1:%d/hook", port)
+	resp, err := http.Post(url, "application/json", nil)
+	if err != nil {
+		t.Fatalf("POST /hook: %v", err)
+	}
+	defer resp.Body.Close()
+	// Empty body -> 400 (bad JSON), but the server is alive
+	// A valid POST should return 200
+	body := `{"session_id":"test","hook_event_name":"Stop","cwd":"/tmp"}`
+	resp2, err := http.Post(url, "application/json", io.NopCloser(
+		io.Reader(strings.NewReader(body)),
+	))
+	if err != nil {
+		t.Fatalf("POST /hook valid: %v", err)
+	}
+	defer resp2.Body.Close()
+	if resp2.StatusCode != http.StatusOK {
+		t.Errorf("status = %d, want 200", resp2.StatusCode)
+	}
+}
+
+func TestHookServerStopsWithDaemon(t *testing.T) {
+	d := newTestDaemon(t)
+
+	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+	port := ln.Addr().(*net.TCPAddr).Port
+	ln.Close()
+
+	d.hookPort = port
+
+	if err := d.Start(); err != nil {
+		t.Fatalf("start: %v", err)
+	}
+
+	d.Stop()
+
+	// Give a moment for shutdown
+	time.Sleep(50 * time.Millisecond)
+
+	// Port should no longer be listening
+	url := fmt.Sprintf("http://127.0.0.1:%d/hook", port)
+	_, err = http.Post(url, "application/json", nil)
+	if err == nil {
+		t.Error("expected connection error after Stop, but POST succeeded")
+	}
+}
+
+func TestHookServerPortBusy(t *testing.T) {
+	d := newTestDaemon(t)
+
+	// Occupy a port
+	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+	defer ln.Close()
+	port := ln.Addr().(*net.TCPAddr).Port
+
+	d.hookPort = port
+
+	// Start should succeed despite port being busy (graceful degradation)
+	if err := d.Start(); err != nil {
+		t.Fatalf("start should succeed even with port busy: %v", err)
+	}
+	defer d.Stop()
+}
+
+func TestPollSlowdown(t *testing.T) {
+	d := newTestDaemon(t)
+
+	// No hook received -> default 5s
+	got := d.currentPollInterval()
+	if got != 5*time.Second {
+		t.Errorf("default poll = %v, want 5s", got)
+	}
+
+	// Simulate recent hook
+	d.mu.Lock()
+	d.lastHookTime = time.Now()
+	d.mu.Unlock()
+
+	got = d.currentPollInterval()
+	if got != 20*time.Second {
+		t.Errorf("after hook poll = %v, want 20s", got)
+	}
+
+	// Simulate hook > 60s ago
+	d.mu.Lock()
+	d.lastHookTime = time.Now().Add(-61 * time.Second)
+	d.mu.Unlock()
+
+	got = d.currentPollInterval()
+	if got != 5*time.Second {
+		t.Errorf("after 60s poll = %v, want 5s", got)
+	}
 }
 
 func TestDaemonStartStop(t *testing.T) {