feat(KB-503): add multi-project CLI support with project subcommands

- Add project subcommands: list, add, remove, show, set-default, detect
- Add --project flag support for all task commands
- Create project-context.ts utilities for project resolution
- Add defaultProjectId to GlobalSettings type
- Implement project auto-detection from cwd
- Update CLI argument parsing for global --project flag
- Add multi-project CLI documentation to AGENTS.md

packages/dashboard/app/components/__tests__/GitManagerModal.test.tsx

@@ -991,8 +991,9 @@ describe("GitManagerModal", () => {
     await user.clear(nameInput);
     await user.type(nameInput, "upstream");
 
-    const saveButton = screen.getByRole("button", { name: "" }); // Check button
-    await user.click(saveButton);
+    const saveButton = nameInput.closest(".gm-remote-edit")?.querySelector(".btn.btn-sm.btn-primary");
+    expect(saveButton).toBeTruthy();
+    await user.click(saveButton as HTMLButtonElement);
 
     await waitFor(() => {
       expect(renameGitRemote).toHaveBeenCalledWith("origin", "upstream");
@@ -1023,8 +1024,9 @@ describe("GitManagerModal", () => {
     await user.clear(urlInput);
     await user.type(urlInput, "https://new-url.com/repo.git");
 
-    const saveButton = screen.getByRole("button", { name: "" }); // Check button
-    await user.click(saveButton);
+    const saveButton = urlInput.closest(".gm-remote-edit")?.querySelector(".btn.btn-sm.btn-primary");
+    expect(saveButton).toBeTruthy();
+    await user.click(saveButton as HTMLButtonElement);
 
     await waitFor(() => {
       expect(updateGitRemoteUrl).toHaveBeenCalledWith("origin", "https://new-url.com/repo.git");