Fix Claude agent interrupt race and refactor mode color tiers

- Fix race in agent-manager where pendingRun wasn't fully cleaned up
  before the next streamAgent call, causing "already has an active run"
- Fix Claude agent query restart: null out query/input before awaiting
  old iterator return so the old pump skips failActiveTurns
- Reset pendingInterruptAbort on new foreground turn
- Add system error assertion to send-during-tool-call e2e test
- Rename mode color tiers: drop "default", rename "readonly" to
  "planning", update color assignments across providers and UI

packages/app/src/components/agent-status-bar.tsx

@@ -106,21 +106,18 @@ function getModeIconColor(
   palette: {
     blue: { 500: string };
     green: { 500: string };
-    amber: { 500: string };
     red: { 500: string };
     purple: { 500: string };
   },
 ): string {
   switch (colorTier) {
-    case "default":
-      return palette.blue[500];
     case "safe":
       return palette.green[500];
     case "moderate":
-      return palette.amber[500];
+      return palette.blue[500];
     case "dangerous":
       return palette.red[500];
-    case "readonly":
+    case "planning":
       return palette.purple[500];
     default:
       return palette.blue[500];