Add configurable worktree root

* Add configurable worktree root

Allow new Paseo worktrees to be created under a custom worktrees.root from config.json while preserving the existing PASEO_HOME/worktrees default. Thread the resolved root through create/list/archive/ownership flows, MCP/session paths, checkout metadata, schema, docs, and targeted tests.

* Address worktree root review feedback

Use the resolved Paseo worktree base when a custom PASEO_HOME is provided, and remove an unused worktreesRoot dependency from worktree list handling.

* Fix checkout worktree path test on Windows

Use platform-native paths in the custom PASEO_HOME regression test so Windows CI compares against the same resolved root shape as production code.

* Clarify optional worktrees config docs

---------

Co-authored-by: Mohamed Boudra <boudra.moha@gmail.com>

packages/server/src/utils/checkout-git.test.ts

@@ -10,6 +10,7 @@ import {
   mkdirSync,
 } from "fs";
 import { join } from "path";
+import { win32 } from "node:path";
 import { tmpdir } from "os";
 import {
   __resetCheckoutShortstatCacheForTests,
@@ -2355,6 +2356,20 @@ const x = 1;
       expect(isPaseoWorktreePath("C:\\Users\\dev\\.paseo\\worktrees\\feature")).toBe(true);
     });
 
+    it("matches worktrees under a custom PASEO_HOME", () => {
+      const customPaseoHome = process.platform === "win32" ? "C:\\paseo" : "/var/lib/paseo";
+      const worktreePath =
+        process.platform === "win32"
+          ? win32.join(customPaseoHome, "worktrees", "project", "feature")
+          : `${customPaseoHome}/worktrees/project/feature`;
+
+      expect(
+        isPaseoWorktreePath(worktreePath, {
+          paseoHome: customPaseoHome,
+        }),
+      ).toBe(true);
+    });
+
     it("rejects paths without .paseo/worktrees segment", () => {
       expect(isPaseoWorktreePath("/home/user/repo")).toBe(false);
       expect(isPaseoWorktreePath("C:\\Users\\dev\\repo")).toBe(false);