test(terminal): close final review coverage gaps

src/renderer/src/components/terminal-pane/pty-transport.ts

@@ -76,6 +76,7 @@ export const MAX_PENDING_PTY_SIDE_EFFECTS = 512
 // Why: agent status is last-wins store state, but payloads can carry KB-scale prompt/tool strings;
 // carry only the newest few through eviction so a status flood cannot re-grow what it evicted.
 export const MAX_EVICTED_AGENT_STATUS_PAYLOAD_CARRY = 16
+const MAX_EVICTED_AGENT_TITLE_TRANSITION_CARRY = 3
 
 type PtyOutputCallbacks = Parameters<PtyTransport['connect']>[0]['callbacks']
 
@@ -218,7 +219,7 @@ export function createPtyOutputProcessor({
         continue
       }
       evictedAgentTitleTransitions.push({ phase, title })
-      if (evictedAgentTitleTransitions.length > 3) {
+      if (evictedAgentTitleTransitions.length > MAX_EVICTED_AGENT_TITLE_TRANSITION_CARRY) {
         evictedAgentTitleTransitions.shift()
       }
     }

src/renderer/src/components/terminal-pane/terminal-eviction-exempt-tabs.test.ts

@@ -56,6 +56,21 @@ describe('selectEvictionExemptTerminalTabLayoutKey', () => {
     )
   })
 
+  it('is stable across leaf-map insertion order', () => {
+    const first = layoutState({
+      [LEAF_ID]: PTY_ID,
+      [SECOND_LEAF_ID]: 'pty-local-detached'
+    })
+    const reversed = layoutState({
+      [SECOND_LEAF_ID]: 'pty-local-detached',
+      [LEAF_ID]: PTY_ID
+    })
+
+    expect(selectEvictionExemptTerminalTabLayoutKey(first, TABS)).toBe(
+      selectEvictionExemptTerminalTabLayoutKey(reversed, TABS)
+    )
+  })
+
   it('tolerates tabs with no persisted layout', () => {
     expect(selectEvictionExemptTerminalTabLayoutKey({ terminalLayoutsByTabId: {} }, TABS)).toBe(
       JSON.stringify([[TAB_ID, []]])