refactor: round-3 pass-1 follow-ups (#30699)

- one repoRowOwnerStamp for the SSH and runtime session placeholder builders
- lineage refresh resolves the transport host once; pin that a server reply never appends a copy
- markdown-document-paths tests live next to the shared module

src/renderer/src/store/slices/worktrees/host-scoped-row-merges.test.ts

@@ -89,4 +89,20 @@ describe('row writers touch only the copy on their own host', () => {
       hostId: 'runtime:hub'
     })
   })
+
+  it("never appends a server's copy when only the local twin is listed", () => {
+    const store = createTestStore()
+    const { local } = seedTwins(store)
+    store.setState({ worktreesByRepo: { [REPO_ID]: [local] } })
+    applyWorktreeLineageUpdate(store.setState, WORKTREE_ID, {
+      target: { kind: 'environment', environmentId: 'hub' },
+      lineage: null,
+      updatedRemoteWorktree: makeWorktree({
+        id: WORKTREE_ID,
+        repoId: REPO_ID,
+        displayName: 'server after lineage'
+      })
+    })
+    expect(store.getState().worktreesByRepo[REPO_ID]).toEqual([local])
+  })
 })

src/renderer/src/store/slices/worktrees/metadata/worktree-lineage-refresh.ts

@@ -189,18 +189,16 @@ export function applyWorktreeLineageUpdate(
     } else {
       delete next[worktreeId]
     }
+    // Why the transport's host: focus can name the local twin of a row a server just answered for.
+    const transportHostId = getRuntimeTargetHostId(result.target)
     const worktreesByRepo =
       result.target.kind === 'local'
         ? projectLocalWorktreeLineageUpdate(s.worktreesByRepo, worktreeId, result.lineage)
         : result.updatedRemoteWorktree
-          ? // Why the transport's host: focus can name the local twin of a row a server just answered for.
-            replaceWorktreeInRepoLists(
+          ? replaceWorktreeInRepoLists(
               s,
-              withRepoHostOwnership(
-                result.updatedRemoteWorktree,
-                getRuntimeTargetHostId(result.target)
-              ),
-              getRuntimeTargetHostId(result.target)
+              withRepoHostOwnership(result.updatedRemoteWorktree, transportHostId),
+              transportHostId
             )
           : s.worktreesByRepo
     return {

src/renderer/src/store/terminals/workspace-terminal-placeholders.ts

@@ -4,9 +4,9 @@ import { DEFAULT_REPO_BADGE_COLOR } from '../../../../shared/constants'
 import {
   getRepoExecutionHostId,
   parseExecutionHostId,
-  toSshExecutionHostId,
   type ExecutionHostId
 } from '../../../../shared/execution-host'
+import { repoRowOwnerStamp } from './workspace-terminal-ssh-placeholders'
 import { parseWorkspaceKey } from '../../../../shared/workspace-scope'
 import { splitWorktreeIdForFilesystem } from '../../../../shared/worktree/id'
 
@@ -16,22 +16,13 @@ export function getPathDisplayName(path: string, fallback: string): string {
   return basename || fallback
 }
 
-/**
- * A server's repo that nests an SSH target lists its worktrees as `ssh:<target>` reached through
- * that server; a bare `runtime:` stamp would hide the target from an `ssh:` host selection.
- */
 function runtimePlaceholderOwner(
   repos: readonly Repo[],
   repoId: string,
   hostId: ExecutionHostId
 ): Pick<Worktree, 'hostId' | 'runtimeOwnerEnvironmentId'> {
-  const host = parseExecutionHostId(hostId)
-  const connectionId = repos
-    .find((repo) => repo.id === repoId && getRepoExecutionHostId(repo) === hostId)
-    ?.connectionId?.trim()
-  return connectionId && host?.kind === 'runtime'
-    ? { hostId: toSshExecutionHostId(connectionId), runtimeOwnerEnvironmentId: host.environmentId }
-    : { hostId }
+  const row = repos.find((repo) => repo.id === repoId && getRepoExecutionHostId(repo) === hostId)
+  return row ? repoRowOwnerStamp(row) : { hostId }
 }
 
 export function buildRuntimeSessionPlaceholders({

src/renderer/src/store/terminals/workspace-terminal-ssh-placeholders.ts

@@ -13,23 +13,33 @@ import {
 
 type PlaceholderOwner = Pick<Worktree, 'hostId' | 'runtimeOwnerEnvironmentId'>
 
+/**
+ * The owner a listing stamps on this repo row's worktrees. A server's repo that nests an SSH
+ * target lists them as `ssh:<target>` through that server, so a bare `runtime:` stamp would hide
+ * the target from an `ssh:` host selection.
+ */
+export function repoRowOwnerStamp(row: Repo): PlaceholderOwner {
+  const host = parseExecutionHostId(getRepoExecutionHostId(row))
+  const connectionId = row.connectionId?.trim()
+  if (host?.kind === 'runtime') {
+    return connectionId
+      ? {
+          hostId: toSshExecutionHostId(connectionId),
+          runtimeOwnerEnvironmentId: host.environmentId
+        }
+      : { hostId: host.id }
+  }
+  // Why: a row whose explicit host disagrees with its connection is not evidence of either.
+  return connectionId && host?.id === toSshExecutionHostId(connectionId) ? { hostId: host.id } : {}
+}
+
 /**
  * The SSH host, and the server proxying it, that a listing would stamp. A repo id with rows on
  * several hosts names neither, so its placeholder stays unstamped rather than guessing a twin.
  */
 function placeholderOwner(repos: readonly Repo[], repoId: string): PlaceholderOwner {
   const rows = repos.filter((repo) => repo.id === repoId)
-  const connectionId = rows.length === 1 ? rows[0].connectionId?.trim() : undefined
-  if (!connectionId) {
-    return {}
-  }
-  const sshHostId = toSshExecutionHostId(connectionId)
-  const host = parseExecutionHostId(getRepoExecutionHostId(rows[0]))
-  if (host?.kind === 'runtime') {
-    return { hostId: sshHostId, runtimeOwnerEnvironmentId: host.environmentId }
-  }
-  // Why: a row whose explicit host disagrees with its connection is not evidence of either.
-  return host?.id === sshHostId ? { hostId: sshHostId } : {}
+  return rows.length === 1 && rows[0].connectionId?.trim() ? repoRowOwnerStamp(rows[0]) : {}
 }
 
 export function addHydratedSshWorktreePlaceholders(

src/shared/markdown-document-paths-windows-client.test.ts

@@ -6,10 +6,7 @@ vi.mock('node:path', async (importOriginal) => {
   return { ...actual, extname: actual.win32.extname }
 })
 
-import {
-  isMarkdownDocumentName,
-  markdownDocumentFromRelativePath
-} from '../../shared/markdown-document-paths'
+import { isMarkdownDocumentName, markdownDocumentFromRelativePath } from './markdown-document-paths'
 
 describe('remote Markdown filenames on a Windows client', () => {
   it('keeps the local filename helper on Windows semantics', () => {

src/shared/markdown-document-paths.test.ts

@@ -2,7 +2,7 @@ import { describe, expect, it } from 'vitest'
 import {
   markdownDocumentFromFilePath,
   markdownDocumentFromRelativePath
-} from '../../shared/markdown-document-paths'
+} from './markdown-document-paths'
 
 describe('markdownDocumentFromFilePath', () => {
   it.skipIf(process.platform === 'win32')('preserves local literal backslash names', () => {