Auth with passwords + Playwright E2E tests + PostHog analytics

- bcrypt password hashing in auth (register, login, change-password)
- Login/register pages with password fields
- Profile update + OAuth placeholder endpoints
- Playwright test suite: auth, pages, API (3 test files)
- PostHog Docker analytics on :8010

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/tasks/lib/api.ts

@@ -35,7 +35,7 @@ async function apiFetch<T>(path: string, opts: ApiOptions = {}): Promise<T> {
 }
 
 // Auth
-export function register(data: { email: string; name: string; phone?: string }) {
+export function register(data: { email: string; name: string; phone?: string; password: string }) {
   return apiFetch<{ data: { token: string; user: User } }>("/api/v1/auth/register", {
     method: "POST",
     body: data,