diff --git a/src/main/ipc/worktree-remote.ts b/src/main/ipc/worktree-remote.ts
index c4ea34e81d3..d0319908122 100644
--- a/src/main/ipc/worktree-remote.ts
+++ b/src/main/ipc/worktree-remote.ts
@@ -135,10 +135,7 @@ import {
   getWorktreeCreateCandidate,
   WORKTREE_CREATE_MAX_SUFFIX_ATTEMPTS
 } from '../worktree-create-candidates'
-import {
-  getRetiredWorktreeNamesForRepo,
-  retireGeneratedWorktreeName
-} from '../worktree-name-retirement'
+import { getRetiredWorktreeNamesForRepo } from '../worktree-name-retirement'
 
 const SSH_WORKTREE_CREATE_FETCH_FRESHNESS_MS = 30_000
 const SSH_WORKTREE_CREATE_FETCH_CACHE_MAX = 512
@@ -1555,7 +1552,7 @@ export async function createRemoteWorktree(
   let lastBranchConflictKind: 'local' | 'remote' | null = null
   let remotePathResolved = false
   const retiredNames = args.nameWasGenerated
-    ? new Set(getRetiredWorktreeNamesForRepo(store, repo, settings))
+    ? new Set(getRetiredWorktreeNamesForRepo(store, repo, store.getRepos(), settings))
     : null
   // Why: duplicate PR/MR checkouts still need a workspace; suffix branch/path while preserving review metadata and push target.
   for (let suffix = 1; suffix <= WORKTREE_CREATE_MAX_SUFFIX_ATTEMPTS; suffix += 1) {
@@ -1773,7 +1770,7 @@ export async function createRemoteWorktree(
   const worktreeId = `${repo.id}::${created.path}`
   // Why: repo-qualified layouts decorate the physical leaf; retire the name main actually used.
   if (args.nameWasGenerated) {
-    retireGeneratedWorktreeName(store, repo, settings, effectiveSanitizedName)
+    store.addRetiredWorktreeName(repo.id, effectiveSanitizedName)
   }
   const now = Date.now()
   // Why: PR/MR worktrees start from a head ref/SHA but Source Control must compare against the review target branch.
@@ -2104,7 +2101,7 @@ export async function createLocalWorktree(
   let lastExistingPR: Awaited<ReturnType<typeof getPRForBranch>> | null = null
   let lastExistingReviewNumber: number | null = null
   const retiredNames = args.nameWasGenerated
-    ? new Set(getRetiredWorktreeNamesForRepo(store, repo, settings))
+    ? new Set(getRetiredWorktreeNamesForRepo(store, repo, store.getRepos(), settings))
     : null
   // Why: a create-from-review branch override may already exist locally; suffix both branch and path instead of blocking the user.
   for (let suffix = 1; suffix <= WORKTREE_CREATE_MAX_SUFFIX_ATTEMPTS; suffix += 1) {
@@ -2400,7 +2397,7 @@ export async function createLocalWorktree(
   const worktreeId = `${repo.id}::${created.path}`
   // Why: repo-qualified layouts decorate the physical leaf; retire the name main actually used.
   if (args.nameWasGenerated) {
-    retireGeneratedWorktreeName(store, repo, settings, effectiveSanitizedName)
+    store.addRetiredWorktreeName(repo.id, effectiveSanitizedName)
   }
   const now = Date.now()
   // Why: PR/MR worktrees start from a head ref/SHA but Source Control must compare against the review target branch.
diff --git a/src/main/ipc/worktrees-windows.test.ts b/src/main/ipc/worktrees-windows.test.ts
index 189f2e55141..8efa7c905fc 100644
--- a/src/main/ipc/worktrees-windows.test.ts
+++ b/src/main/ipc/worktrees-windows.test.ts
@@ -348,7 +348,7 @@ describe('registerWorktreeHandlers – Windows path handling', () => {
       nameWasGenerated: true
     })
 
-    expect(store.addRetiredWorktreeName).toHaveBeenCalledWith(expect.any(String), 'nautilus-2')
+    expect(store.addRetiredWorktreeName).toHaveBeenCalledWith('repo-1', 'nautilus-2')
   })
 
   it('leaves a user-typed name reusable even when the same name is retired', async () => {
diff --git a/src/main/ipc/worktrees.test.ts b/src/main/ipc/worktrees.test.ts
index 460f6e62b85..3ea8e2cfc35 100644
--- a/src/main/ipc/worktrees.test.ts
+++ b/src/main/ipc/worktrees.test.ts
@@ -4715,7 +4715,7 @@ describe('registerWorktreeHandlers', () => {
     )
     expect(provider.listWorktrees).toHaveBeenCalledTimes(1)
     expect(provider.worktreeIsClean).not.toHaveBeenCalled()
-    expect(store.addRetiredWorktreeName).toHaveBeenCalledWith(expect.any(String), 'nautilus-2')
+    expect(store.addRetiredWorktreeName).toHaveBeenCalledWith('repo-ssh', 'nautilus-2')
     expect(store.setWorktreeMeta).toHaveBeenCalledWith(
       'repo-ssh::/remote/repo-nautilus-2',
       expect.objectContaining({
diff --git a/src/main/ipc/worktrees.ts b/src/main/ipc/worktrees.ts
index 62620720d21..a5335ca20de 100644
--- a/src/main/ipc/worktrees.ts
+++ b/src/main/ipc/worktrees.ts
@@ -1925,7 +1925,7 @@ export function registerWorktreeHandlers(
       // Best effort: without the seed we only under-retire, which is the pre-existing behavior.
       console.warn(`[worktrees] retirement backfill failed for repo ${args.repoId}:`, err)
     }
-    return getRetiredWorktreeNamesForRepo(store, repo, store.getSettings())
+    return getRetiredWorktreeNamesForRepo(store, repo, store.getRepos(), store.getSettings())
   })
 
   ipcMain.handle('worktrees:list', async (_event, args: { repoId: string }) => {
diff --git a/src/main/orca-profiles/profile-project-source-removal.ts b/src/main/orca-profiles/profile-project-source-removal.ts
index edb923e6293..b120ba0c372 100644
--- a/src/main/orca-profiles/profile-project-source-removal.ts
+++ b/src/main/orca-profiles/profile-project-source-removal.ts
@@ -18,6 +18,7 @@ export function removeSourceRepo(
     ...state,
     repos: state.repos.filter((repo) => repo.id !== repoId),
     sparsePresetsByRepo: { ...state.sparsePresetsByRepo },
+    retiredWorktreeNamesByRepo: { ...state.retiredWorktreeNamesByRepo },
     worktreeMeta: { ...state.worktreeMeta },
     worktreeLineageById: { ...state.worktreeLineageById },
     workspaceLineageByChildKey: { ...state.workspaceLineageByChildKey },
@@ -38,6 +39,7 @@ export function removeSourceRepo(
     }
   }
   delete next.sparsePresetsByRepo[repoId]
+  delete next.retiredWorktreeNamesByRepo?.[repoId]
   removeRepoWorktreeMetadata(next, repoId)
   return rebuildRepoBackedProjectState(next)
 }
diff --git a/src/main/orca-profiles/profile-project-state-file.ts b/src/main/orca-profiles/profile-project-state-file.ts
index 4169fea6ffc..bd7fbc8f6be 100644
--- a/src/main/orca-profiles/profile-project-state-file.ts
+++ b/src/main/orca-profiles/profile-project-state-file.ts
@@ -45,6 +45,7 @@ export function readProfileState(profileId: string, userDataPath: string): Trans
     projectGroups: arrayOrEmpty(parsed.projectGroups),
     folderWorkspaces: arrayOrEmpty(parsed.folderWorkspaces),
     sparsePresetsByRepo: recordOrEmpty<SparsePreset[]>(parsed.sparsePresetsByRepo),
+    retiredWorktreeNamesByRepo: recordOrEmpty<string[]>(parsed.retiredWorktreeNamesByRepo),
     worktreeMeta: recordOrEmpty(parsed.worktreeMeta),
     worktreeLineageById: recordOrEmpty(parsed.worktreeLineageById),
     workspaceLineageByChildKey: recordOrEmpty(parsed.workspaceLineageByChildKey),
diff --git a/src/main/orca-profiles/profile-project-transfer-payload.ts b/src/main/orca-profiles/profile-project-transfer-payload.ts
index f8e458df4df..524aa02ad92 100644
--- a/src/main/orca-profiles/profile-project-transfer-payload.ts
+++ b/src/main/orca-profiles/profile-project-transfer-payload.ts
@@ -20,6 +20,9 @@ import {
 export type TransferPayload = {
   repo: Repo
   sparsePresets: SparsePreset[]
+  /** Generated names already spent for this repo. Carried so the destination profile does not
+   *  reissue a name whose old directory still holds agent state. */
+  retiredWorktreeNames: string[]
   worktreeMeta: PersistedState['worktreeMeta']
   worktreeLineageById: PersistedState['worktreeLineageById']
   workspaceLineageByChildKey: PersistedState['workspaceLineageByChildKey']
@@ -214,6 +217,7 @@ export function createTransferPayload(args: {
       ...structuredClone(preset),
       repoId: newRepoId
     })),
+    retiredWorktreeNames: [...(sourceState.retiredWorktreeNamesByRepo?.[oldRepoId] ?? [])],
     worktreeMeta: rekeyWorktreeIdRecord(
       sourceState.worktreeMeta,
       worktreeIds,
@@ -269,6 +273,13 @@ export function applyPayloadToTarget(
       ...targetState.sparsePresetsByRepo,
       ...(payload.sparsePresets.length > 0 ? { [payload.repo.id]: payload.sparsePresets } : {})
     },
+    retiredWorktreeNamesByRepo: {
+      ...targetState.retiredWorktreeNamesByRepo,
+      ...(payload.retiredWorktreeNames.length > 0
+        ? { [payload.repo.id]: payload.retiredWorktreeNames }
+        : {})
+    },
+
     worktreeMeta: { ...targetState.worktreeMeta, ...payload.worktreeMeta },
     worktreeLineageById: { ...targetState.worktreeLineageById, ...payload.worktreeLineageById },
     workspaceLineageByChildKey: {
diff --git a/src/main/orca-profiles/profile-project-transfer.test.ts b/src/main/orca-profiles/profile-project-transfer.test.ts
index 3c3a4643387..a8983dc4979 100644
--- a/src/main/orca-profiles/profile-project-transfer.test.ts
+++ b/src/main/orca-profiles/profile-project-transfer.test.ts
@@ -126,6 +126,7 @@ describe('profile project transfer', () => {
             }
           ]
         },
+        retiredWorktreeNamesByRepo: { 'repo-1': ['nautilus'] },
         worktreeMeta: {
           [sourceWorktreeId]: makeWorktreeMeta({ projectHostSetupId: 'repo-1' })
         },
@@ -177,6 +178,9 @@ describe('profile project transfer', () => {
     expect(target.sparsePresetsByRepo[targetRepoId]).toEqual([
       expect.objectContaining({ id: 'preset-1', repoId: targetRepoId })
     ])
+    // Why: without the re-key the destination profile reissues a name whose old directory may
+    // still hold the previous occupant's agent conversation.
+    expect(target.retiredWorktreeNamesByRepo?.[targetRepoId]).toEqual(['nautilus'])
     expect(target.workspaceSession.tabsByWorktree).toEqual({})
     expect(readProfileState('personal').repos.map((repo) => repo.id)).toEqual(['repo-1'])
   })
diff --git a/src/main/persistence-worktree-name-retirement.test.ts b/src/main/persistence-worktree-name-retirement.test.ts
index 8e296c880d4..6522e3bae0a 100644
--- a/src/main/persistence-worktree-name-retirement.test.ts
+++ b/src/main/persistence-worktree-name-retirement.test.ts
@@ -3,6 +3,7 @@ import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from 'node:fs'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { getDefaultPersistedState } from '../shared/constants'
+import { MARINE_CREATURES } from '../shared/marine-creatures'
 
 const testState = { dir: '' }
 
@@ -13,9 +14,8 @@ vi.mock('electron', () => ({
 vi.mock('./telemetry/client', () => ({ track: vi.fn() }))
 vi.mock('./telemetry/cohort-classifier', () => ({ getCohortAtEmit: vi.fn() }))
 
-// The registry is keyed by the cwd namespace a repo creates into, not by repo id.
-const KEY = 'local:posix:/workspaces/repo-1'
-const OTHER_KEY = 'local:posix:/workspaces/repo-2'
+const REPO = 'repo-1'
+const OTHER_REPO = 'repo-2'
 
 async function createStore(persisted: Record<string, unknown> = {}) {
   mkdirSync(testState.dir, { recursive: true })
@@ -41,81 +41,134 @@ afterEach(() => {
 describe('worktree name retirement registry', () => {
   it('retains a retired name so it is never reissued', async () => {
     const store = await createStore()
-    store.addRetiredWorktreeName(KEY, 'Nautilus')
-    expect(store.getRetiredWorktreeNames(KEY)).toEqual(['nautilus'])
+    store.addRetiredWorktreeName(REPO, 'Nautilus')
+    expect(store.getRetiredWorktreeNames(REPO)).toEqual(['nautilus'])
   })
 
-  it('scopes retirement per cwd namespace so one workspace root does not burn another', async () => {
+  it('scopes retirement per repo so one repo does not burn another pool', async () => {
     const store = await createStore()
-    store.addRetiredWorktreeName(KEY, 'nautilus')
-    expect(store.getRetiredWorktreeNames(OTHER_KEY)).toEqual([])
+    store.addRetiredWorktreeName(REPO, 'nautilus')
+    expect(store.getRetiredWorktreeNames(OTHER_REPO)).toEqual([])
   })
 
   it('normalizes case and whitespace so a name cannot be retired twice', async () => {
     const store = await createStore()
-    store.addRetiredWorktreeName(KEY, '  NaUtIlUs ')
-    store.addRetiredWorktreeName(KEY, 'nautilus')
-    expect(store.getRetiredWorktreeNames(KEY)).toEqual(['nautilus'])
+    store.addRetiredWorktreeName(REPO, '  NaUtIlUs ')
+    store.addRetiredWorktreeName(REPO, 'nautilus')
+    expect(store.getRetiredWorktreeNames(REPO)).toEqual(['nautilus'])
   })
 
-  it('ignores an empty name or missing workspace key', async () => {
+  it('ignores an empty name or missing repo id', async () => {
     const store = await createStore()
-    store.addRetiredWorktreeName(KEY, '   ')
+    store.addRetiredWorktreeName(REPO, '   ')
     store.addRetiredWorktreeName('', 'nautilus')
-    expect(store.getRetiredWorktreeNames(KEY)).toEqual([])
+    expect(store.getRetiredWorktreeNames(REPO)).toEqual([])
   })
 
   it('does not persist arbitrary user and issue-title names', async () => {
     const store = await createStore()
-    store.addRetiredWorktreeName(KEY, 'fix-login-redirect')
-    store.addRetiredWorktreeName(KEY, 'STA-4189-duplicate-name')
-    expect(store.getRetiredWorktreeNames(KEY)).toEqual([])
+    store.addRetiredWorktreeName(REPO, 'fix-login-redirect')
+    store.addRetiredWorktreeName(REPO, 'STA-4189-duplicate-name')
+    expect(store.getRetiredWorktreeNames(REPO)).toEqual([])
   })
 
   it('returns a copy so callers cannot mutate the registry in place', async () => {
     const store = await createStore()
-    store.addRetiredWorktreeName(KEY, 'nautilus')
-    store.getRetiredWorktreeNames(KEY).push('seahorse')
-    expect(store.getRetiredWorktreeNames(KEY)).toEqual(['nautilus'])
+    store.addRetiredWorktreeName(REPO, 'nautilus')
+    store.getRetiredWorktreeNames(REPO).push('seahorse')
+    expect(store.getRetiredWorktreeNames(REPO)).toEqual(['nautilus'])
   })
 
   it('merges backfilled names without dropping a concurrent retirement', async () => {
     const store = await createStore()
-    store.addRetiredWorktreeName(KEY, 'nautilus')
-    expect(store.mergeRetiredWorktreeNames(KEY, ['seahorse', 'starfish'])).toBe(true)
-    expect(store.getRetiredWorktreeNames(KEY).sort()).toEqual(['nautilus', 'seahorse', 'starfish'])
+    store.addRetiredWorktreeName(REPO, 'nautilus')
+    expect(store.mergeRetiredWorktreeNames(REPO, ['seahorse', 'starfish'])).toBe(true)
+    expect(store.getRetiredWorktreeNames(REPO).sort()).toEqual(['nautilus', 'seahorse', 'starfish'])
   })
 
   it('reports no change when a merge adds nothing new', async () => {
     const store = await createStore()
-    store.addRetiredWorktreeName(KEY, 'nautilus')
-    expect(store.mergeRetiredWorktreeNames(KEY, ['NAUTILUS'])).toBe(false)
+    store.addRetiredWorktreeName(REPO, 'nautilus')
+    expect(store.mergeRetiredWorktreeNames(REPO, ['NAUTILUS'])).toBe(false)
   })
 
   it('survives a reload so retirement outlives the workspace and the app session', async () => {
     const store = await createStore({
-      retiredWorktreeNamesByWorkspaceKey: { [KEY]: ['nautilus', 'seahorse'] }
+      retiredWorktreeNamesByRepo: { [REPO]: ['nautilus', 'seahorse'] }
     })
-    expect(store.getRetiredWorktreeNames(KEY).sort()).toEqual(['nautilus', 'seahorse'])
+    expect(store.getRetiredWorktreeNames(REPO).sort()).toEqual(['nautilus', 'seahorse'])
   })
 
   it('degrades to nothing retired when the persisted map is corrupt', async () => {
     // Why: a load failure costs the app; over- or under-retiring costs at most a name.
-    const store = await createStore({ retiredWorktreeNamesByWorkspaceKey: 'not-an-object' })
-    expect(store.getRetiredWorktreeNames(KEY)).toEqual([])
+    const store = await createStore({ retiredWorktreeNamesByRepo: 'not-an-object' })
+    expect(store.getRetiredWorktreeNames(REPO)).toEqual([])
   })
 
   it('drops non-string entries but keeps the valid ones', async () => {
     const store = await createStore({
-      retiredWorktreeNamesByWorkspaceKey: { [KEY]: ['nautilus', 42, null, 'Seahorse'] }
+      retiredWorktreeNamesByRepo: { [REPO]: ['nautilus', 42, null, 'Seahorse'] }
     })
-    expect(store.getRetiredWorktreeNames(KEY).sort()).toEqual(['nautilus', 'seahorse'])
+    expect(store.getRetiredWorktreeNames(REPO).sort()).toEqual(['nautilus', 'seahorse'])
+  })
+
+  it('drops the registry when the repo is removed, matching the sparse-preset convention', async () => {
+    // Why: entries are repo-id keyed, so without this they orphan forever — a repo id is never
+    // reused, and remove/re-add mints a new one.
+    const store = await createStore()
+    store.addRepo({ id: REPO, path: '/repos/a', displayName: 'a', badgeColor: '', addedAt: 0 })
+    store.addRetiredWorktreeName(REPO, 'nautilus')
+
+    store.removeProject(REPO)
+
+    expect(store.getRetiredWorktreeNames(REPO)).toEqual([])
+  })
+
+  it('keeps the registry when one host row is removed but the repo id survives elsewhere', async () => {
+    const store = await createStore()
+    store.addRepo({ id: REPO, path: '/repos/a', displayName: 'a', badgeColor: '', addedAt: 0 })
+    store.addRepo({
+      id: REPO,
+      path: '/repos/a',
+      displayName: 'a',
+      badgeColor: '',
+      addedAt: 0,
+      executionHostId: 'runtime:env-1'
+    } as never)
+    store.addRetiredWorktreeName(REPO, 'nautilus')
+
+    store.removeProjectForHost(REPO, 'runtime:env-1')
+
+    expect(store.getRetiredWorktreeNames(REPO)).toEqual(['nautilus'])
+
+    store.removeProjectForHost(REPO, 'local')
+
+    expect(store.getRetiredWorktreeNames(REPO)).toEqual([])
+  })
+
+  it('bounds the per-repo registry above the pool so the cap never reissues a base name', async () => {
+    // The cap must sit well past the 552-name pool: evicting inside it would hand back a name whose
+    // agent state is still on disk, which is the bug this registry exists to prevent.
+    const store = await createStore()
+    const names = MARINE_CREATURES.map((name) => name.toLowerCase())
+    for (let tier = 2; tier <= 5; tier += 1) {
+      store.mergeRetiredWorktreeNames(
+        REPO,
+        names.map((name) => `${name}-${tier}`)
+      )
+    }
+    store.mergeRetiredWorktreeNames(REPO, names)
+
+    const retained = store.getRetiredWorktreeNames(REPO)
+    expect(retained.length).toBe(2000)
+    // Oldest-first eviction, so the most recent merge survives intact.
+    expect(retained).toEqual(expect.arrayContaining(names))
   })
 
   it('drops legacy arbitrary names while loading the persisted map', async () => {
     const store = await createStore({
-      retiredWorktreeNamesByWorkspaceKey: { [KEY]: ['fix-login', 'Nautilus'] }
+      retiredWorktreeNamesByRepo: { [REPO]: ['fix-login', 'Nautilus'] }
     })
-    expect(store.getRetiredWorktreeNames(KEY)).toEqual(['nautilus'])
+    expect(store.getRetiredWorktreeNames(REPO)).toEqual(['nautilus'])
   })
 })
diff --git a/src/main/persistence.ts b/src/main/persistence.ts
index 22eea861a07..0aee1c2bd16 100644
--- a/src/main/persistence.ts
+++ b/src/main/persistence.ts
@@ -2335,15 +2335,28 @@ const MAX_CLAUDE_LIVE_PTY_SESSION_IDS = 200
 // Why: bound removed-SSH-target history so remove/re-add churn can't grow the file unbounded.
 const MAX_REMOVED_SSH_TARGET_TOMBSTONES = 50
 
+// Why: bound per-repo retirement so long-lived repos can't grow the file unbounded. Deliberately
+// far above the 552-name pool — a cap below it would start reissuing names and reintroduce the bug
+// this registry exists to prevent, so only `-2`/`-3` tier accumulation can ever reach it.
+const MAX_RETIRED_WORKTREE_NAMES_PER_REPO = 2000
+
+/** Oldest-first eviction: entries are appended in retirement order, and the oldest paths are the
+ *  ones whose agent state is likeliest to be gone already. */
+function boundRetiredWorktreeNames(names: readonly string[]): string[] {
+  return names.length > MAX_RETIRED_WORKTREE_NAMES_PER_REPO
+    ? names.slice(names.length - MAX_RETIRED_WORKTREE_NAMES_PER_REPO)
+    : [...names]
+}
+
 /** Why: a corrupt or hand-edited map must degrade to "nothing retired" rather than throw during
  *  load — over-retiring costs one name from a 552-entry pool, but a load failure costs the app. */
-function normalizeRetiredWorktreeNamesByWorkspaceKey(value: unknown): Record<string, string[]> {
+function normalizeRetiredWorktreeNamesByRepo(value: unknown): Record<string, string[]> {
   if (!value || typeof value !== 'object' || Array.isArray(value)) {
     return {}
   }
-  const byKey: Record<string, string[]> = {}
-  for (const [workspaceKey, names] of Object.entries(value as Record<string, unknown>)) {
-    if (!workspaceKey || !Array.isArray(names)) {
+  const byRepo: Record<string, string[]> = {}
+  for (const [repoId, names] of Object.entries(value as Record<string, unknown>)) {
+    if (!repoId || !Array.isArray(names)) {
       continue
     }
     const seen = new Set<string>()
@@ -2357,10 +2370,10 @@ function normalizeRetiredWorktreeNamesByWorkspaceKey(value: unknown): Record<str
       }
     }
     if (seen.size > 0) {
-      byKey[workspaceKey] = [...seen]
+      byRepo[repoId] = boundRetiredWorktreeNames([...seen])
     }
   }
-  return byKey
+  return byRepo
 }
 
 function normalizeClaudeLivePtySessionIds(value: unknown): string[] {
@@ -3848,8 +3861,8 @@ export class Store {
                 (alias): alias is string => typeof alias === 'string'
               )
             : [],
-          retiredWorktreeNamesByWorkspaceKey: normalizeRetiredWorktreeNamesByWorkspaceKey(
-            parsed.retiredWorktreeNamesByWorkspaceKey
+          retiredWorktreeNamesByRepo: normalizeRetiredWorktreeNamesByRepo(
+            parsed.retiredWorktreeNamesByRepo
           ),
           sshRemotePtyLeases: (parsed.sshRemotePtyLeases ?? [])
             .map(normalizeSshRemotePtyLease)
@@ -4881,6 +4894,8 @@ export class Store {
     this.syncProjectHostSetupCompatibilityState()
     // Why: presets are repo-scoped and unreachable once the repo is gone, so drop them with it.
     delete this.state.sparsePresetsByRepo[id]
+    // Same convention: retirements are repo-id-keyed, so they would otherwise orphan forever.
+    delete this.state.retiredWorktreeNamesByRepo?.[id]
     this.pruneWorktreeStateForRepo(id, null)
     this.state.workspaceSession = removeRepoFromWorkspaceSession(this.state.workspaceSession, id)
     this.state.workspaceSessionsByHostId = removeRepoFromHostWorkspaceSessions(
@@ -4896,9 +4911,11 @@ export class Store {
       (r) => !(r.id === id && getRepoExecutionHostId(r) === hostId)
     )
     const idStillPresent = this.state.repos.some((r) => r.id === id)
-    // Why: presets are repo-id-scoped (not host-scoped); drop them only when the last host's copy is gone.
+    // Why: presets and retirements are repo-id-scoped (not host-scoped); drop them only when the
+    // last host's copy is gone.
     if (!idStillPresent) {
       delete this.state.sparsePresetsByRepo[id]
+      delete this.state.retiredWorktreeNamesByRepo?.[id]
     }
     this.syncProjectHostSetupCompatibilityState()
     // Why: prune only this host's worktree metas if the id survives elsewhere; otherwise prune everything (matches removeProject).
@@ -7215,32 +7232,32 @@ export class Store {
     this.scheduleSave()
   }
 
-  getRetiredWorktreeNames(workspaceKey: string): string[] {
-    return [...(this.state.retiredWorktreeNamesByWorkspaceKey?.[workspaceKey] ?? [])]
+  getRetiredWorktreeNames(repoId: string): string[] {
+    return [...(this.state.retiredWorktreeNamesByRepo?.[repoId] ?? [])]
   }
 
-  /** Records a generated workspace name as spent in this cwd namespace. Called with the name main
-   *  actually used, not the one the renderer proposed — create can advance past it on collision. */
-  addRetiredWorktreeName(workspaceKey: string, name: string): void {
+  /** Records a generated workspace name as spent for this repo. Called with the name main actually
+   *  used, not the one the renderer proposed — the create path can advance past it on collision. */
+  addRetiredWorktreeName(repoId: string, name: string): void {
     const normalized = normalizeRetirableGeneratedName(name)
-    if (!workspaceKey || !normalized) {
+    if (!repoId || !normalized) {
       return
     }
-    this.state.retiredWorktreeNamesByWorkspaceKey ??= {}
-    const existing = this.state.retiredWorktreeNamesByWorkspaceKey[workspaceKey]
+    this.state.retiredWorktreeNamesByRepo ??= {}
+    const existing = this.state.retiredWorktreeNamesByRepo[repoId]
     if (existing?.includes(normalized)) {
       return
     }
-    this.state.retiredWorktreeNamesByWorkspaceKey[workspaceKey] = existing
-      ? [...existing, normalized]
-      : [normalized]
+    this.state.retiredWorktreeNamesByRepo[repoId] = boundRetiredWorktreeNames(
+      existing ? [...existing, normalized] : [normalized]
+    )
     this.scheduleSave()
   }
 
   /** Seeds retirements discovered by the one-time backfill. Merges rather than replaces so a
    *  concurrent create during backfill is not lost. Returns true when anything was added. */
-  mergeRetiredWorktreeNames(workspaceKey: string, names: Iterable<string>): boolean {
-    if (!workspaceKey) {
+  mergeRetiredWorktreeNames(repoId: string, names: Iterable<string>): boolean {
+    if (!repoId) {
       return false
     }
     const incoming = new Set<string>()
@@ -7253,8 +7270,8 @@ export class Store {
     if (incoming.size === 0) {
       return false
     }
-    this.state.retiredWorktreeNamesByWorkspaceKey ??= {}
-    const existing = this.state.retiredWorktreeNamesByWorkspaceKey[workspaceKey] ?? []
+    this.state.retiredWorktreeNamesByRepo ??= {}
+    const existing = this.state.retiredWorktreeNamesByRepo[repoId] ?? []
     const merged = new Set(existing)
     for (const name of incoming) {
       merged.add(name)
@@ -7262,7 +7279,7 @@ export class Store {
     if (merged.size === existing.length) {
       return false
     }
-    this.state.retiredWorktreeNamesByWorkspaceKey[workspaceKey] = [...merged]
+    this.state.retiredWorktreeNamesByRepo[repoId] = boundRetiredWorktreeNames([...merged])
     this.scheduleSave()
     return true
   }
diff --git a/src/main/runtime/orca-runtime.test.ts b/src/main/runtime/orca-runtime.test.ts
index 7013b17b05f..9081df980d1 100644
--- a/src/main/runtime/orca-runtime.test.ts
+++ b/src/main/runtime/orca-runtime.test.ts
@@ -4092,7 +4092,7 @@ describe('OrcaRuntimeService', () => {
         worktrees: expect.arrayContaining([expect.objectContaining({ path: createdWorktree.path })])
       }
     )
-    expect(addRetiredWorktreeName).toHaveBeenCalledWith(expect.any(String), 'nautilus-2')
+    expect(addRetiredWorktreeName).toHaveBeenCalledWith(TEST_REPO_ID, 'nautilus-2')
   })
 
   it('neither skips nor retires a name the user typed', async () => {
diff --git a/src/main/runtime/orca-runtime.ts b/src/main/runtime/orca-runtime.ts
index 5c4995b776d..2efcbf73f03 100644
--- a/src/main/runtime/orca-runtime.ts
+++ b/src/main/runtime/orca-runtime.ts
@@ -936,8 +936,7 @@ import {
 } from '../worktree-create-candidates'
 import {
   ensureRetiredWorktreeNamesBackfilled,
-  getRetiredWorktreeNamesForRepo,
-  retireGeneratedWorktreeName
+  getRetiredWorktreeNamesForRepo
 } from '../worktree-name-retirement'
 import { normalizeSparseDirectories } from '../ipc/sparse-checkout-directories'
 import type { PtyBindingSourceExpectation, Store } from '../persistence'
@@ -21180,7 +21179,7 @@ export class OrcaRuntimeService {
     } catch (error) {
       console.warn(`[runtime] retirement backfill failed for repo ${repo.id}:`, error)
     }
-    return { [repo.id]: getRetiredWorktreeNamesForRepo(store, repo, settings) }
+    return { [repo.id]: getRetiredWorktreeNamesForRepo(store, repo, store.getRepos(), settings) }
   }
 
   async listDetectedManagedWorktrees(
@@ -22374,7 +22373,7 @@ export class OrcaRuntimeService {
     let worktreePath = ''
     let worktreePathResolved = false
     const retiredNames = args.nameWasGenerated
-      ? new Set(getRetiredWorktreeNamesForRepo(this.store, repo, settings))
+      ? new Set(getRetiredWorktreeNamesForRepo(this.store, repo, this.store.getRepos(), settings))
       : null
     // Why: runtime/mobile create-from-review callers should get a new workspace
     // even when the PR branch or review branch name is already in use.
@@ -22707,7 +22706,7 @@ export class OrcaRuntimeService {
     const worktreeId = `${repo.id}::${created.path}`
     // Why: repo-qualified layouts decorate the physical leaf; retire the name main actually used.
     if (args.nameWasGenerated) {
-      retireGeneratedWorktreeName(this.store, repo, settings, effectiveSanitizedName)
+      this.store.addRetiredWorktreeName(repo.id, effectiveSanitizedName)
     }
     const now = Date.now()
     // Why: PR/MR-created worktrees can start from a head ref/SHA while Source
diff --git a/src/main/worktree-name-retirement.test.ts b/src/main/worktree-name-retirement.test.ts
index 52b23b35a4e..d298dccb431 100644
--- a/src/main/worktree-name-retirement.test.ts
+++ b/src/main/worktree-name-retirement.test.ts
@@ -11,8 +11,7 @@ import {
   extractBucketLeafCandidates,
   getRetiredWorktreeNamesForRepo,
   normalizeRetirableGeneratedName,
-  resetRetirementCollisionKeyCacheForTests,
-  retireGeneratedWorktreeName
+  resetRetirementCollisionKeyCacheForTests
 } from './worktree-name-retirement'
 
 const FIRST = MARINE_CREATURES[0].toLowerCase()
@@ -201,62 +200,67 @@ describe('discoverRetiredWorktreeNames', () => {
 describe('getRetiredWorktreeNamesForRepo', () => {
   const settingsFor = (nestWorkspaces: boolean): GlobalSettings =>
     ({ workspaceDir: '/workspaces', nestWorkspaces }) as GlobalSettings
+  const storeOf = (byRepo: Record<string, string[]>) => {
+    const calls: string[] = []
+    return {
+      calls,
+      getRetiredWorktreeNames: (repoId: string) => {
+        calls.push(repoId)
+        return byRepo[repoId] ?? []
+      }
+    }
+  }
 
   it('shares retirements when two repos create into the same cwd namespace', () => {
-    const byKey = new Map<string, string[]>()
-    const store = {
-      getRetiredWorktreeNames: (key: string) => byKey.get(key) ?? [],
-      addRetiredWorktreeName: (key: string, name: string) =>
-        byKey.set(key, [...(byKey.get(key) ?? []), name])
-    }
-    const settings = settingsFor(false)
-    const repoA = makeRepo('repo-a', '/repos/a')
-    const repoB = makeRepo('repo-b', '/repos/b')
+    const store = storeOf({ 'repo-a': [FIRST], 'repo-b': [SECOND] })
+    const repos = [makeRepo('repo-a', '/repos/a'), makeRepo('repo-b', '/repos/b')]
 
-    retireGeneratedWorktreeName(store, repoA, settings, FIRST)
-
-    expect(getRetiredWorktreeNamesForRepo(store, repoB, settings)).toEqual([FIRST])
+    expect(
+      getRetiredWorktreeNamesForRepo(store, repos[1], repos, settingsFor(false)).sort()
+    ).toEqual([FIRST, SECOND].sort())
   })
 
   it('keeps independent nested repo paths in separate retirement domains', () => {
-    const byKey = new Map<string, string[]>()
-    const store = {
-      getRetiredWorktreeNames: (key: string) => byKey.get(key) ?? [],
-      addRetiredWorktreeName: (key: string, name: string) =>
-        byKey.set(key, [...(byKey.get(key) ?? []), name])
-    }
-    const settings = settingsFor(true)
-    const repoA = makeRepo('repo-a', '/repos/a')
-    const repoB = makeRepo('repo-b', '/repos/b')
+    const store = storeOf({ 'repo-a': [FIRST], 'repo-b': [SECOND] })
+    const repos = [makeRepo('repo-a', '/repos/a'), makeRepo('repo-b', '/repos/b')]
 
-    retireGeneratedWorktreeName(store, repoA, settings, FIRST)
-
-    expect(getRetiredWorktreeNamesForRepo(store, repoB, settings)).toEqual([])
-    expect(getRetiredWorktreeNamesForRepo(store, repoA, settings)).toEqual([FIRST])
+    expect(getRetiredWorktreeNamesForRepo(store, repos[1], repos, settingsFor(true))).toEqual([
+      SECOND
+    ])
   })
 
-  it('survives a repo being removed and re-added under a new id', () => {
-    // Why: repo ids are regenerated on re-add. Keying the registry by repo id silently dropped
-    // every retirement for a path that had not changed at all.
-    const byKey = new Map<string, string[]>()
-    const store = {
-      getRetiredWorktreeNames: (key: string) => byKey.get(key) ?? [],
-      addRetiredWorktreeName: (key: string, name: string) =>
-        byKey.set(key, [...(byKey.get(key) ?? []), name])
+  it('never probes a path for peers that hold no retirements', () => {
+    // Why: deriving a peer's namespace runs computeWorktreePath, which for a WSL repo is a blocking
+    // wsl.exe call. Reading `path` is exactly what a probe does, so count that.
+    const pathReads: string[] = []
+    const spyRepo = (id: string, path: string): Repo => {
+      const repo = makeRepo(id, path)
+      return Object.defineProperty(repo, 'path', {
+        get: () => {
+          pathReads.push(id)
+          return path
+        }
+      }) as Repo
     }
-    const settings = settingsFor(true)
+    const store = storeOf({ 'repo-a': [FIRST] })
+    const repos = [
+      spyRepo('repo-a', '/repos/a'),
+      ...Array.from({ length: 20 }, (_unused, index) => spyRepo(`peer-${index}`, `/repos/${index}`))
+    ]
 
-    retireGeneratedWorktreeName(store, makeRepo('repo-old', '/repos/a'), settings, FIRST)
-
-    expect(
-      getRetiredWorktreeNamesForRepo(store, makeRepo('repo-new', '/repos/a'), settings)
-    ).toEqual([FIRST])
+    expect(getRetiredWorktreeNamesForRepo(store, repos[0], repos, settingsFor(false))).toEqual([
+      FIRST
+    ])
+    expect(pathReads.filter((id) => id.startsWith('peer-'))).toEqual([])
   })
 
   it('reports nothing for a folder workspace, which has no generated worktree names', () => {
-    const store = { getRetiredWorktreeNames: () => [FIRST] }
+    const store = storeOf({ folder: [FIRST] })
     const folderRepo = { ...makeRepo('folder', '/repos/folder'), kind: 'folder' as const }
-    expect(getRetiredWorktreeNamesForRepo(store, folderRepo, settingsFor(false))).toEqual([])
+
+    expect(
+      getRetiredWorktreeNamesForRepo(store, folderRepo, [folderRepo], settingsFor(false))
+    ).toEqual([])
   })
 })
 
@@ -265,24 +269,26 @@ describe('ensureRetiredWorktreeNamesBackfilled', () => {
     const root = await mkdtemp(join(tmpdir(), 'orca-retirement-backfill-'))
     const workspaceRoot = join(root, 'workspaces')
     await mkdir(join(workspaceRoot, FIRST), { recursive: true })
-    const merged: { key: string; names: string[] }[] = []
+    const merged: { repoId: string; names: string[] }[] = []
     const store = {
-      mergeRetiredWorktreeNames: (key: string, names: Iterable<string>) => {
-        merged.push({ key, names: [...names] })
+      mergeRetiredWorktreeNames: (repoId: string, names: Iterable<string>) => {
+        merged.push({ repoId, names: [...names] })
         return true
       }
     }
-    const repo = makeRepo('repo-a', join(root, 'repos', 'a'))
     const settings = { workspaceDir: workspaceRoot, nestWorkspaces: false }
 
     try {
-      await ensureRetiredWorktreeNamesBackfilled(store, repo, settings)
-      expect(merged).toHaveLength(1)
-      expect(merged[0].names).toContain(FIRST)
+      await ensureRetiredWorktreeNamesBackfilled(store, makeRepo('repo-a', '/repos/a'), settings)
+      expect(merged).toEqual([{ repoId: 'repo-a', names: [FIRST] }])
 
-      // A second repo in the same namespace reuses the one in-flight scan.
+      // Why: the scan is cached per cwd namespace but the registry is per repo, so a second repo in
+      // the same namespace must still receive the merge rather than silently inheriting nothing.
       await ensureRetiredWorktreeNamesBackfilled(store, makeRepo('repo-b', '/repos/b'), settings)
-      expect(merged).toHaveLength(1)
+      expect(merged).toEqual([
+        { repoId: 'repo-a', names: [FIRST] },
+        { repoId: 'repo-b', names: [FIRST] }
+      ])
     } finally {
       await rm(root, { force: true, recursive: true })
     }
@@ -291,7 +297,7 @@ describe('ensureRetiredWorktreeNamesBackfilled', () => {
   it('skips repos whose agent state lives on another host', async () => {
     const merged: string[] = []
     const store = {
-      mergeRetiredWorktreeNames: (_key: string, names: Iterable<string>) => {
+      mergeRetiredWorktreeNames: (_repoId: string, names: Iterable<string>) => {
         merged.push(...names)
         return true
       }
diff --git a/src/main/worktree-name-retirement.ts b/src/main/worktree-name-retirement.ts
index 7698270bc37..a46c4b0b2b2 100644
--- a/src/main/worktree-name-retirement.ts
+++ b/src/main/worktree-name-retirement.ts
@@ -18,16 +18,13 @@ import {
 import { worktreePathComparisonKey } from './ipc/worktree-path-comparison'
 
 const RETIREMENT_PROBE_NAME = 'orca-retirement-probe'
-const backfillsByStore = new WeakMap<object, Map<string, Promise<void>>>()
+const scansByStore = new WeakMap<object, Map<string, Promise<Set<string>>>>()
 
 type RetirementReadStore = {
-  getRetiredWorktreeNames(collisionKey: string): string[]
-}
-type RetirementWriteStore = {
-  addRetiredWorktreeName(collisionKey: string, name: string): void
+  getRetiredWorktreeNames(repoId: string): string[]
 }
 type RetirementBackfillStore = {
-  mergeRetiredWorktreeNames(collisionKey: string, names: Iterable<string>): boolean
+  mergeRetiredWorktreeNames(repoId: string, names: Iterable<string>): boolean
 }
 type RetirementPathSettings = Pick<GlobalSettings, 'nestWorkspaces' | 'workspaceDir'>
 
@@ -121,29 +118,40 @@ export function getRetirementCollisionKey(repo: Repo, settings: RetirementPathSe
   return key
 }
 
+/** Stored per repo id, which is stable, but read across every repo that creates into the same cwd
+ *  namespace — that is where a reissued name would actually collide.
+ *
+ *  The peer scan is deliberately lazy: a repo's own retirements never touch a path, and a peer's
+ *  namespace is derived only once that peer is known to hold retirements. Deriving one costs a
+ *  blocking `wsl.exe` call for a WSL repo, so it must not be paid per repo on every create. */
 export function getRetiredWorktreeNamesForRepo(
   store: RetirementReadStore,
   repo: Repo,
+  repos: readonly Repo[],
   settings: RetirementPathSettings
 ): string[] {
   if (isFolderRepo(repo)) {
     return []
   }
-  return store.getRetiredWorktreeNames(getRetirementCollisionKey(repo, settings))
-}
-
-/** Records the name main actually used, not the one the client proposed — the create path can
- *  advance past a taken candidate. Call only for names Orca generated. */
-export function retireGeneratedWorktreeName(
-  store: RetirementWriteStore,
-  repo: Repo,
-  settings: RetirementPathSettings,
-  name: string
-): void {
-  if (isFolderRepo(repo)) {
-    return
+  const names = new Set(store.getRetiredWorktreeNames(repo.id))
+  let collisionKey: string | null = null
+  for (const candidate of repos) {
+    if (candidate.id === repo.id || isFolderRepo(candidate)) {
+      continue
+    }
+    const candidateNames = store.getRetiredWorktreeNames(candidate.id)
+    if (candidateNames.length === 0) {
+      continue
+    }
+    collisionKey ??= getRetirementCollisionKey(repo, settings)
+    if (getRetirementCollisionKey(candidate, settings) !== collisionKey) {
+      continue
+    }
+    for (const name of candidateNames) {
+      names.add(name)
+    }
   }
-  store.addRetiredWorktreeName(getRetirementCollisionKey(repo, settings), name)
+  return [...names]
 }
 
 function parentPath(path: string): string {
@@ -157,27 +165,29 @@ export function ensureRetiredWorktreeNamesBackfilled(
   repo: Repo,
   settings: RetirementPathSettings
 ): Promise<void> {
-  // Remote workspaces keep their agent state on the execution host, which this scan cannot see.
+  // Remote workspaces keep their agent state on the execution host, which this scan cannot see, so
+  // a re-added SSH repo does not recover its retirements the way a local one does.
   if (isFolderRepo(repo) || repo.connectionId) {
     return Promise.resolve()
   }
-  let storeBackfills = backfillsByStore.get(store)
-  if (!storeBackfills) {
-    storeBackfills = new Map()
-    backfillsByStore.set(store, storeBackfills)
+  let storeScans = scansByStore.get(store)
+  if (!storeScans) {
+    storeScans = new Map()
+    scansByStore.set(store, storeScans)
   }
   const collisionKey = getRetirementCollisionKey(repo, settings)
-  const existing = storeBackfills.get(collisionKey)
-  if (existing) {
-    return existing
+  let scan = storeScans.get(collisionKey)
+  if (!scan) {
+    scan = discoverRetiredWorktreeNames({
+      workspaceRoots: [parentPath(getRetirementProbePath(repo, settings))]
+    })
+    storeScans.set(collisionKey, scan)
   }
-  const backfill = discoverRetiredWorktreeNames({
-    workspaceRoots: [parentPath(getRetirementProbePath(repo, settings))]
-  }).then((names) => {
-    store.mergeRetiredWorktreeNames(collisionKey, names)
+  // Why the merge sits outside the cached promise: the scan is per cwd namespace but the registry
+  // is per repo, so every repo that asks must receive it — not only the one that triggered it.
+  return scan.then((names) => {
+    store.mergeRetiredWorktreeNames(repo.id, names)
   })
-  storeBackfills.set(collisionKey, backfill)
-  return backfill
 }
 
 async function readDirectoryNames(path: string): Promise<string[]> {
diff --git a/src/shared/constants.ts b/src/shared/constants.ts
index 7a860143d1f..3610ad224f7 100644
--- a/src/shared/constants.ts
+++ b/src/shared/constants.ts
@@ -431,7 +431,7 @@ export function getDefaultPersistedState(homedir: string): PersistedState {
     projectGroups: [],
     folderWorkspaces: [],
     sparsePresetsByRepo: {},
-    retiredWorktreeNamesByWorkspaceKey: {},
+    retiredWorktreeNamesByRepo: {},
     worktreeMeta: {},
     worktreeLineageById: {},
     workspaceLineageByChildKey: {},
diff --git a/src/shared/types.ts b/src/shared/types.ts
index a8dd14962a8..9be84019b4d 100644
--- a/src/shared/types.ts
+++ b/src/shared/types.ts
@@ -3742,12 +3742,13 @@ export type PersistedState = {
   folderWorkspaceDiffComments?: Record<string, DiffComment[]>
   /** Sparse-checkout presets keyed by repoId. */
   sparsePresetsByRepo: Record<string, SparsePreset[]>
-  /** Generated workspace names already issued, keyed by the cwd namespace repos create into
-   *  (execution host + workspace-root path), not by repoId — the collision this prevents is on the
-   *  path, and repo ids change on remove/re-add while the path does not. Suppresses reissuing a
-   *  name so a recreated workspace never lands on a prior occupant's path and inherits agent state
-   *  keyed to that cwd. Grows monotonically; entries are never removed on workspace deletion. */
-  retiredWorktreeNamesByWorkspaceKey?: Record<string, string[]>
+  /** Generated workspace names already issued, keyed by repoId. Suppresses reissuing a name so a
+   *  recreated workspace never lands on a prior occupant's path and inherits agent state keyed to
+   *  that cwd. Grows monotonically within a repo — entries are never removed on workspace deletion
+   *  — and is dropped wholesale when the repo is removed. Readers union across every repo that
+   *  creates into the same cwd namespace, so the storage key stays the stable repo id while the
+   *  guarantee follows the path. */
+  retiredWorktreeNamesByRepo?: Record<string, string[]>
   /** Per paired device last tab selection by worktree; keeps mobile navigation across host restarts. */
   mobileClientTabSelectionsByDeviceId?: PersistedMobileClientTabSelections
   worktreeMeta: Record<string, WorktreeMeta>