fix(tui): demote gateway log-noise from Activity to info tone

Restore the old-CLI contract where only complete failures tint Activity
red. Everything else is still visible for debugging but no longer
commandeers attention.

- gateway.stderr: always tone='info' (drops the ERRLIKE_RE regex)
- gateway.protocol_error: both pushes demoted to 'info'
- commands.catalog cold-start failure: demoted to 'info'
- approval.request: no longer duplicates the overlay into Activity

Kept as 'error': terminal `error` event, gateway.start_timeout,
gateway-exited, explicit status.update kinds.

ui-tui/src/__tests__/createGatewayEventHandler.test.ts

@@ -1,9 +1,9 @@
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 
 import { createGatewayEventHandler } from '../app/createGatewayEventHandler.js'
-import { resetOverlayState } from '../app/overlayStore.js'
+import { getOverlayState, resetOverlayState } from '../app/overlayStore.js'
 import { turnController } from '../app/turnController.js'
-import { resetTurnState } from '../app/turnStore.js'
+import { getTurnState, resetTurnState } from '../app/turnStore.js'
 import { patchUiState, resetUiState } from '../app/uiStore.js'
 import { estimateTokensRough } from '../lib/text.js'
 import type { Msg } from '../types.js'
@@ -273,4 +273,42 @@ describe('createGatewayEventHandler', () => {
       role: 'system'
     })
   })
+
+  it('keeps gateway noise informational and approval out of Activity', async () => {
+    const appended: Msg[] = []
+    const ctx = buildCtx(appended)
+    ctx.gateway.rpc = vi.fn(async () => {
+      throw new Error('cold start')
+    })
+
+    const onEvent = createGatewayEventHandler(ctx)
+
+    onEvent({ payload: { line: 'Traceback: noisy but non-fatal' }, type: 'gateway.stderr' } as any)
+    onEvent({ payload: { preview: 'bad framing' }, type: 'gateway.protocol_error' } as any)
+    onEvent({
+      payload: { command: 'rm -rf /tmp/nope', description: 'dangerous command' },
+      type: 'approval.request'
+    } as any)
+    onEvent({ payload: {}, type: 'gateway.ready' } as any)
+
+    await Promise.resolve()
+    await Promise.resolve()
+
+    expect(getOverlayState().approval).toMatchObject({ description: 'dangerous command' })
+    expect(getTurnState().activity).toMatchObject([
+      { text: 'Traceback: noisy but non-fatal', tone: 'info' },
+      { text: 'protocol noise detected · /logs to inspect', tone: 'info' },
+      { text: 'protocol noise: bad framing', tone: 'info' },
+      { text: 'command catalog unavailable: cold start', tone: 'info' }
+    ])
+  })
+
+  it('still surfaces terminal turn failures as errors', () => {
+    const appended: Msg[] = []
+    const onEvent = createGatewayEventHandler(buildCtx(appended))
+
+    onEvent({ payload: { message: 'boom' }, type: 'error' } as any)
+
+    expect(getTurnState().activity).toMatchObject([{ text: 'boom', tone: 'error' }])
+  })
 })