fix(server): preserve selected workspace root (#361)

Fixes #202

## Summary
- keep the default `root` worktree directory pointed at the folder the
user opened
- continue using the git repo root only for git/worktree discovery
- add a targeted regression test for opening a repo subfolder as the
workspace

## Why
When a workspace is opened from a subfolder inside a git repo, CodeNomad
currently maps the `root` worktree to the repo root. That causes proxied
OpenCode requests to run with the repo root directory and miss an
`opencode.json` that lives in the selected subfolder.

## Validation
- inspected the attached `config-issue.zip` from #202
- confirmed `resolveRepoRoot(proj-1)` still returns the git root while
`listWorktrees()` now returns `root.directory = proj-1`
- `npx tsx --test
"packages/server/src/workspaces/__tests__/git-worktrees.test.ts"`
- `npm run typecheck --workspace @neuralnomads/codenomad`

packages/server/src/workspaces/__tests__/git-worktrees.test.ts

@@ -0,0 +1,47 @@
+import assert from "node:assert/strict"
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs"
+import { tmpdir } from "node:os"
+import path from "node:path"
+import { describe, it } from "node:test"
+import { listWorktrees } from "../git-worktrees"
+
+describe("listWorktrees", () => {
+  it("uses the selected workspace folder for the root worktree directory", async () => {
+    const temp = mkdtempSync(path.join(tmpdir(), "codenomad-git-worktrees-"))
+    const binDir = path.join(temp, "bin")
+    const repoRoot = path.join(temp, "repo")
+    const workspaceFolder = path.join(repoRoot, "proj-1")
+    const originalPath = process.env.PATH
+
+    try {
+      mkdirSync(binDir, { recursive: true })
+      mkdirSync(workspaceFolder, { recursive: true })
+
+      const gitPath = path.join(binDir, process.platform === "win32" ? "git.cmd" : "git")
+      const porcelain = [
+        `worktree ${repoRoot}`,
+        "HEAD 1111111",
+        "branch refs/heads/main",
+        "",
+      ].join("\\n")
+
+      if (process.platform === "win32") {
+        writeFileSync(gitPath, `@echo off\r\nif "%1"=="worktree" if "%2"=="list" if "%3"=="--porcelain" (\r\necho ${porcelain.replace(/\n/g, "\r\necho ")}\r\nexit /b 0\r\n)\r\nexit /b 1\r\n`)
+      } else {
+        writeFileSync(gitPath, `#!/bin/sh\nif [ "$1" = "worktree" ] && [ "$2" = "list" ] && [ "$3" = "--porcelain" ]; then\nprintf '%s\n' '${porcelain.replace(/'/g, "'\\''")}'\nexit 0\nfi\nexit 1\n`, { mode: 0o755 })
+      }
+
+      process.env.PATH = `${binDir}${path.delimiter}${originalPath ?? ""}`
+
+      const worktrees = await listWorktrees({ repoRoot, workspaceFolder })
+
+      assert.equal(worktrees[0]?.slug, "root")
+      assert.equal(worktrees[0]?.directory, workspaceFolder)
+      assert.equal(worktrees[0]?.kind, "root")
+      assert.notEqual(worktrees[0]?.directory, repoRoot)
+    } finally {
+      process.env.PATH = originalPath
+      rmSync(temp, { recursive: true, force: true })
+    }
+  })
+})

packages/server/src/workspaces/git-worktrees.ts

@@ -105,7 +105,7 @@ export async function listWorktrees(params: {
 
   const result = await runGit(["worktree", "list", "--porcelain"], workspaceFolder)
   if (!result.ok) {
-    const rootDescriptor: WorktreeDescriptor = { slug: "root", directory: repoRoot, kind: "root" }
+    const rootDescriptor: WorktreeDescriptor = { slug: "root", directory: workspaceFolder, kind: "root" }
     logger?.debug?.({ repoRoot, err: result.error }, "Failed to list git worktrees; returning root only")
     return [rootDescriptor]
   }
@@ -114,7 +114,7 @@ export async function listWorktrees(params: {
   const rootRecord = records.find((record) => path.resolve(record.worktree) === path.resolve(repoRoot))
   const rootDescriptor: WorktreeDescriptor = {
     slug: "root",
-    directory: repoRoot,
+    directory: workspaceFolder,
     kind: "root",
     branch: rootRecord?.branch,
   }