feat(migration): implement workspace layout migration and testing

- Added `migrate-layout.ts` to handle migration from old workspace layouts to the new `devclaw/` structure.
- Introduced `migrate-layout.test.ts` for comprehensive tests covering various migration scenarios.
- Updated `workspace.ts` to ensure default files are created post-migration, including `workflow.yaml` and role-specific prompts.
- Refactored role instruction handling to accommodate new directory structure.
- Enhanced project registration to scaffold prompt files in the new `devclaw/projects/<project>/prompts/` directory.
- Adjusted setup tool descriptions and logic to reflect changes in file structure.
- Updated templates to align with the new workflow configuration and role instructions.

lib/tools/design-task.test.ts

@@ -31,9 +31,9 @@ describe("architect tiers", () => {
     assert.strictEqual(getDefaultModel("architect", "junior"), "anthropic/claude-sonnet-4-5");
   });
 
-  it("should resolve architect model from config", () => {
-    const config = { models: { architect: { senior: "custom/model" } } };
-    assert.strictEqual(resolveModel("architect", "senior", config), "custom/model");
+  it("should resolve architect model from resolved role config", () => {
+    const resolvedRole = { models: { senior: "custom/model" }, levels: ["junior", "senior"], defaultLevel: "junior", emoji: {}, completionResults: [] as string[], enabled: true };
+    assert.strictEqual(resolveModel("architect", "senior", resolvedRole), "custom/model");
   });
 
   it("should have architect emoji", () => {