fix: restore coarse running busy signal (#2023)

apps/backend/internal/profiles/profiles.yaml

@@ -67,6 +67,13 @@ features:
     dev:  "false"
     e2e:  "false"
 
+  # High-risk Claude-only background prompt handoff experiment. Off in every
+  # profile so it is exercised only by contributors who deliberately opt in.
+  KANDEV_FEATURES_CLAUDE_BACKGROUND_PROMPT_HANDOFF:
+    prod: "false"
+    dev:  "false"
+    e2e:  "false"
+
 # ── Mock providers ────────────────────────────────────────────────
 # Swap real third-party services for in-memory fakes. Production
 # leaves all of these unset (real APIs). Dev opts into the mock agent

apps/backend/internal/profiles/profiles_test.go

@@ -22,8 +22,8 @@ func TestApplyProfile_DefaultsToProd(t *testing.T) {
 		t.Errorf("env = %q, want %q (no selector env vars set)", env, EnvProd)
 	}
 	// Prod writes each registered feature flag with its safe shipped default.
-	if count != 4 {
-		t.Errorf("ApplyProfile wrote %d vars in prod; want 4", count)
+	if count != 5 {
+		t.Errorf("ApplyProfile wrote %d vars in prod; want 5", count)
 	}
 	if v := os.Getenv("KANDEV_FEATURES_OFFICE"); v != "false" {
 		t.Errorf("KANDEV_FEATURES_OFFICE = %q after prod ApplyProfile; want %q", v, "false")
@@ -37,6 +37,13 @@ func TestApplyProfile_DefaultsToProd(t *testing.T) {
 	if v := os.Getenv("KANDEV_FEATURES_AUTH"); v != "false" {
 		t.Errorf("KANDEV_FEATURES_AUTH = %q after prod ApplyProfile; want %q", v, "false")
 	}
+	if v := os.Getenv("KANDEV_FEATURES_CLAUDE_BACKGROUND_PROMPT_HANDOFF"); v != "false" {
+		t.Errorf(
+			"KANDEV_FEATURES_CLAUDE_BACKGROUND_PROMPT_HANDOFF = %q after prod ApplyProfile; want %q",
+			v,
+			"false",
+		)
+	}
 }
 
 // TestApplyProfile_DevUsesDevelopmentDefaults verifies the mixed dev profile:
@@ -67,6 +74,13 @@ func TestApplyProfile_DevUsesDevelopmentDefaults(t *testing.T) {
 	if v := os.Getenv("KANDEV_FEATURES_AUTH"); v != "false" {
 		t.Errorf("KANDEV_FEATURES_AUTH = %q in dev; want %q", v, "false")
 	}
+	if v := os.Getenv("KANDEV_FEATURES_CLAUDE_BACKGROUND_PROMPT_HANDOFF"); v != "false" {
+		t.Errorf(
+			"KANDEV_FEATURES_CLAUDE_BACKGROUND_PROMPT_HANDOFF = %q in dev; want %q",
+			v,
+			"false",
+		)
+	}
 }
 
 // TestApplyProfile_E2EWinsOverDev checks the documented detection
@@ -92,6 +106,13 @@ func TestApplyProfile_E2EWinsOverDev(t *testing.T) {
 	if v := os.Getenv("AGENTCTL_AUTO_APPROVE_PERMISSIONS"); v != "true" {
 		t.Errorf("AGENTCTL_AUTO_APPROVE_PERMISSIONS = %q in e2e; want %q", v, "true")
 	}
+	if v := os.Getenv("KANDEV_FEATURES_CLAUDE_BACKGROUND_PROMPT_HANDOFF"); v != "false" {
+		t.Errorf(
+			"KANDEV_FEATURES_CLAUDE_BACKGROUND_PROMPT_HANDOFF = %q in e2e; want %q",
+			v,
+			"false",
+		)
+	}
 }
 
 // TestApplyProfile_ExistingEnvWins is the precedence guarantee that
@@ -154,6 +175,13 @@ func TestFeatureFlagDefaults_LowercasesShortName(t *testing.T) {
 	if _, ok := defaults["app_status_bar"]; !ok {
 		t.Errorf("FeatureFlagDefaults missing %q key; got %#v", "app_status_bar", defaults)
 	}
+	if _, ok := defaults["claude_background_prompt_handoff"]; !ok {
+		t.Errorf(
+			"FeatureFlagDefaults missing %q key; got %#v",
+			"claude_background_prompt_handoff",
+			defaults,
+		)
+	}
 }
 
 func TestMarkApplied_OnlyAllowsKnownDerivedEnvVars(t *testing.T) {
@@ -181,7 +209,15 @@ func TestMarkApplied_OnlyAllowsKnownDerivedEnvVars(t *testing.T) {
 // hell out of whoever debugs it.
 func TestProfilesYAML_ContainsRequiredSections(t *testing.T) {
 	yaml := string(ProfilesYAML())
-	for _, section := range []string{"features:", "mocks:", "debug:", "KANDEV_FEATURES_OFFICE:", "KANDEV_FEATURES_PLUGINS:", "KANDEV_FEATURES_APP_STATUS_BAR:"} {
+	for _, section := range []string{
+		"features:",
+		"mocks:",
+		"debug:",
+		"KANDEV_FEATURES_OFFICE:",
+		"KANDEV_FEATURES_PLUGINS:",
+		"KANDEV_FEATURES_APP_STATUS_BAR:",
+		"KANDEV_FEATURES_CLAUDE_BACKGROUND_PROMPT_HANDOFF:",
+	} {
 		if !strings.Contains(yaml, section) {
 			t.Errorf("embedded profiles.yaml missing section/key %q; embed broken or file truncated", section)
 		}