feat(web): self-service cheie/creds + admin web + email signup (PRD 3.3b)

US-007: rute web proprii /cont/roteste-cheie + /cont/rar-creds scoped pe
sesiune (C13), sectiune "Contul meu" cu cheie afisata o data.
US-010: rol admin (users.is_admin) + require_admin->403 + CLI set-admin +
bootstrap primul cont=admin (count_admins in BEGIN IMMEDIATE, anti-race).
US-011: panou /admin (activare/dezactivare conturi, CSRF + PRG), link admin
+ logout pe dashboard.
US-012: app/email.py notify_signup best-effort degradat fara SMTP + config smtp_*.
Fix: migrare defensiva users.is_admin/email_verified in _migrate.

VERIFY x2 context curat (PASS) + /code-review high. 393 teste pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/config.py

@@ -46,6 +46,15 @@ class Settings(BaseSettings):
     # False (dev): cookie fara Secure, functioneaza pe HTTP.
     session_https_only: bool = False
 
+    # --- Notificare email admin la signup (US-012, PRD 3.3b) ---
+    # Nesetat (smtp_host None) -> notificarea e DEGRADATA (doar log SIGNUP);
+    # follow-up cand exista SMTP real configurat in .env.
+    smtp_host: str | None = None
+    smtp_port: int = 587
+    smtp_user: str | None = None
+    smtp_password: str | None = None
+    smtp_from: str | None = None
+
     # --- Rate-limit signup + login (US-009, PRD 3.3 C5) ---
     # Max cereri POST /signup per IP in fereastra de timp (in-proces, fara dependinta noua).
     signup_rate_max: int = 5