fix(repos): stop the retry advice contradicting itself, and cover the runtime lane

Readiness review, two recommendations.

The retry message contradicted itself. After the most common first-run git
failure (unconfigured user.email), the first error says a leftover .git must be
removed before retrying — and the second attempt then answered "Choose a
different name or location", which is the wrong remedy and contradicts what the
user just read. We cannot distinguish a user's own repository from a .git a
failed attempt left behind, so the message now names both remedies.

The runtime lane had zero coverage for either new behaviour, and it is the lane
paired web and remote-desktop clients use: every existing createRepo test passes
kind:'folder', which skips the git branch entirely. Added two real-filesystem
tests — an existing .git directory, and the .git *pointer file* form used by
linked worktrees and submodules — each asserting the refusal and that the bytes
we did not create are still on disk afterwards. Mocked fs cannot prove that.

Both mutation-tested: removing the runtime refusal turns both red.

src/main/ipc/repos/repository-creation-messages.ts

@@ -6,8 +6,10 @@
 export const LEFTOVER_GIT_DIR_RETRY_HINT =
   'If a .git directory was left behind, remove it before retrying.'
 
+// Why: name both remedies. We cannot tell a user's own repository from a .git a failed attempt
+// left behind, and offering only "pick another location" contradicts the retry hint they just read.
 export function alreadyARepositoryError(name: string): string {
-  return `"${name}" is already a git repository. Choose a different name or location.`
+  return `"${name}" is already a git repository. Choose a different name or location — or, if an earlier attempt left a .git directory behind, remove it and try again.`
 }
 
 // Why: a probe that did not complete is not evidence of absence, so we refuse — but as a

src/main/runtime/orca-runtime.test.ts

@@ -14,7 +14,7 @@ import { EventEmitter } from 'node:events'
 import { createHash, randomUUID } from 'node:crypto'
 import { execFileSync } from 'node:child_process'
 import { mkdirSync } from 'node:fs'
-import { lstat, mkdir, mkdtemp, rm, writeFile } from 'node:fs/promises'
+import { lstat, mkdir, mkdtemp, readFile, rm, writeFile } from 'node:fs/promises'
 import { homedir, tmpdir } from 'node:os'
 import { basename, join, win32 } from 'node:path'
 import { ipcMain } from 'electron'
@@ -9374,6 +9374,50 @@ describe('OrcaRuntimeService', () => {
     }
   })
 
+  // Why real bytes: this lane serves paired web and remote-desktop clients, and the behaviour
+  // under test is "a .git that is not ours must still be on disk afterwards". A mocked fs cannot
+  // prove that.
+  it('refuses a runtime create into an existing repository and leaves its .git intact', async () => {
+    const runtime = new OrcaRuntimeService(store as never)
+    const parentDir = await mkdtemp('/tmp/orca-runtime-existing-repo-')
+    try {
+      const target = join(parentDir, 'existing')
+      await mkdir(join(target, '.git'), { recursive: true })
+      await writeFile(join(target, '.git', 'HEAD'), 'ref: refs/heads/main\n')
+
+      const result = await runtime.createRepo(parentDir, 'existing', 'git')
+
+      expect(result).toMatchObject({
+        error: expect.stringContaining('already a git repository')
+      })
+      await expect(readFile(join(target, '.git', 'HEAD'), 'utf8')).resolves.toBe(
+        'ref: refs/heads/main\n'
+      )
+    } finally {
+      await rm(parentDir, { recursive: true, force: true })
+    }
+  })
+
+  it('refuses a runtime create when the target holds a .git pointer file', async () => {
+    // Linked worktrees and submodules point with a `.git` FILE, not a directory.
+    const runtime = new OrcaRuntimeService(store as never)
+    const parentDir = await mkdtemp('/tmp/orca-runtime-gitfile-')
+    try {
+      const target = join(parentDir, 'linked')
+      await mkdir(target, { recursive: true })
+      await writeFile(join(target, '.git'), 'gitdir: /somewhere/.git/worktrees/linked\n')
+
+      const result = await runtime.createRepo(parentDir, 'linked', 'git')
+
+      expect(result).toMatchObject({
+        error: expect.stringContaining('already a git repository')
+      })
+      await expect(readFile(join(target, '.git'), 'utf8')).resolves.toContain('gitdir:')
+    } finally {
+      await rm(parentDir, { recursive: true, force: true })
+    }
+  })
+
   it('defaults runtime createRepo badgeColor to DEFAULT_REPO_BADGE_COLOR', async () => {
     const added: Record<string, unknown>[] = []
     const colorStore = {