fix(mcp/agentic_watch): default 30m → 60s + per-call cap at 30m

defaultWatchTimeout reduced to 60s; new maxWatchTimeout 30m caps any
per-call WatchInput.Timeout. resolveWatchTimeout() honours the request
value (in seconds), clamps above-cap, and treats <=0 as default.

Defends against connection-pool drain from idle long-poll subscribers
whether internal-only today or future external-facing.

Tests: default = 60s, 10s honoured, 10h clamps to 30m, 0 falls back.

Co-authored-by: Codex <noreply@openai.com>
Closes tasks.lthn.sh/view.php?id=1005

pkg/mcp/agentic/watch.go

@@ -14,7 +14,8 @@ import (
 
 const (
 	defaultWatchPollInterval = 5 * time.Second
-	defaultWatchTimeout      = 30 * time.Minute
+	defaultWatchTimeout      = 60 * time.Second
+	maxWatchTimeout          = 30 * time.Minute
 )
 
 // WatchInput is the input for agentic_watch.
@@ -57,10 +58,7 @@ func (s *PrepSubsystem) watch(ctx context.Context, req *mcp.CallToolRequest, inp
 		pollInterval = defaultWatchPollInterval
 	}
 
-	timeout := time.Duration(input.Timeout) * time.Second
-	if timeout <= 0 {
-		timeout = defaultWatchTimeout
-	}
+	timeout := resolveWatchTimeout(input)
 
 	start := time.Now()
 	deadline := start.Add(timeout)
@@ -166,6 +164,19 @@ func (s *PrepSubsystem) watch(ctx context.Context, req *mcp.CallToolRequest, inp
 	}, nil
 }
 
+func resolveWatchTimeout(input WatchInput) time.Duration {
+	if input.Timeout <= 0 {
+		return defaultWatchTimeout
+	}
+
+	maxSeconds := int(maxWatchTimeout / time.Second)
+	if input.Timeout > maxSeconds {
+		return maxWatchTimeout
+	}
+
+	return time.Duration(input.Timeout) * time.Second
+}
+
 func (s *PrepSubsystem) findActiveWorkspaces() []string {
 	wsDirs := s.listWorkspaceDirs()
 	if len(wsDirs) == 0 {

pkg/mcp/agentic/watch_test.go

@@ -7,11 +7,35 @@ import (
 	"time"
 )
 
-func TestWatchDefaults_Good_RFCThirtyMinuteTimeout(t *testing.T) {
-	if defaultWatchTimeout != 30*time.Minute {
-		t.Fatalf("expected default watch timeout to be 30m, got %s", defaultWatchTimeout)
+func TestWatchDefaults_Good_RFCOneMinuteTimeout(t *testing.T) {
+	if defaultWatchTimeout != 60*time.Second {
+		t.Fatalf("expected default watch timeout to be 60s, got %s", defaultWatchTimeout)
 	}
 	if defaultWatchPollInterval != 5*time.Second {
 		t.Fatalf("expected default poll interval to be 5s, got %s", defaultWatchPollInterval)
 	}
+	if maxWatchTimeout != 30*time.Minute {
+		t.Fatalf("expected max watch timeout to be 30m, got %s", maxWatchTimeout)
+	}
+}
+
+func TestResolveWatchTimeout_Good_HonorsInputTimeout(t *testing.T) {
+	got := resolveWatchTimeout(WatchInput{Timeout: 10})
+	if got != 10*time.Second {
+		t.Fatalf("expected input timeout to be honored as 10s, got %s", got)
+	}
+}
+
+func TestResolveWatchTimeout_Good_ClampsInputTimeout(t *testing.T) {
+	got := resolveWatchTimeout(WatchInput{Timeout: int((10 * time.Hour) / time.Second)})
+	if got != 30*time.Minute {
+		t.Fatalf("expected input timeout to clamp to 30m, got %s", got)
+	}
+}
+
+func TestResolveWatchTimeout_Good_ZeroUsesDefault(t *testing.T) {
+	got := resolveWatchTimeout(WatchInput{Timeout: 0})
+	if got != defaultWatchTimeout {
+		t.Fatalf("expected zero timeout to use default %s, got %s", defaultWatchTimeout, got)
+	}
 }