fix(hibernation): never hibernate floating-workspace terminals (#29790)

* fix(hibernation): never hibernate floating-workspace terminals

* docs(hibernation): clarify floating terminal idle policy

---------

Co-authored-by: m4air <m4air@Mac.localdomain>

src/renderer/src/lib/agent-hibernation-planner.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, it } from 'vitest'
 import type { AgentStatusEntry } from '../../../shared/agent-status-types'
+import { FLOATING_TERMINAL_WORKTREE_ID } from '../../../shared/constants'
 import type { TerminalLayoutSnapshot, TerminalTab } from '../../../shared/terminal-tab-types'
 import {
   DEFAULT_AGENT_HIBERNATION_IDLE_MS,
@@ -101,6 +102,21 @@ describe('agent sleep planner', () => {
     expect(plannedWorktrees(snapshot({ foregroundTerminalTabIds: ['tab-1'] }))).toEqual([])
   })
 
+  it('never plans automatic hibernation for a floating-workspace pane', () => {
+    expect(plannedWorktrees(snapshot())).toEqual(['wt-bg'])
+    const floating = entry({ worktreeId: FLOATING_TERMINAL_WORKTREE_ID })
+    expect(
+      plannedWorktrees(
+        snapshot({
+          tabsByWorktree: {
+            [FLOATING_TERMINAL_WORKTREE_ID]: [tab('tab-1', FLOATING_TERMINAL_WORKTREE_ID)]
+          },
+          agentStatusByPaneKey: { [floating.paneKey]: floating }
+        })
+      )
+    ).toEqual([])
+  })
+
   it('requires done resumable provider-session entries', () => {
     for (const state of ['working', 'waiting', 'blocked'] as const) {
       const e = entry({ state })

src/renderer/src/lib/agent-hibernation-planner.ts

@@ -1,4 +1,5 @@
 import type { AgentStatusEntry } from '../../../shared/agent-status-types'
+import { FLOATING_TERMINAL_WORKTREE_ID } from '../../../shared/constants'
 import type { TerminalTab } from '../../../shared/terminal-tab-types'
 import {
   getEligiblePane,
@@ -119,6 +120,10 @@ export function planAgentHibernationCandidates(
     if (!worktreeId || tabs.length === 0) {
       continue
     }
+    // Floating terminals stay running when idle; the user must not need a hibernation resume.
+    if (worktreeId === FLOATING_TERMINAL_WORKTREE_ID) {
+      continue
+    }
     if (
       runtimeLivenessRequiredWorktreeIds.has(worktreeId) &&
       !Object.hasOwn(snapshot.runtimeLivePtyIdsByWorktreeId ?? {}, worktreeId)