Replaces the static bearer-token gate with a real auth boundary. The
existing CASSANDRA_TOKEN path is retained as an admin / scripting escape
hatch — kept compatible by aliasing require_token to require_auth.
- New users table (migration 0007): email, argon2 password_hash, tier,
email_verified (declared but not enforced until phase E), settings_json
for the tone/analysis/anchor knobs we'll wire in phase D.
- app/services/auth_service.py: argon2-cffi password hashing with timing-
attack-resistant authenticate() (always runs a hash verify even on
unknown-email to deny a username-enumeration oracle).
- app/auth.py rewritten: require_auth returns a CurrentUser with either
is_admin=True (bearer path) or a User object (session path). Failing
requests get 303 → /login for HTML, 401 for API. Sessions signed with
itsdangerous against CASSANDRA_SESSION_SECRET; 14-day TTL.
- app/routers/auth.py: /login, /signup, /logout. Login form preserves the
?next=… param for redirect-after-login. Signup respects a new
CASSANDRA_SIGNUP_ENABLED flag.
- Standalone /login + /signup templates (no app chrome). base.html grows
a user chip + logout link in the header (reads request.state.current_user).
Phase A's main known limitations are documented in the plan: email
verification is declared but not enforced; session revocation is
best-effort (cookie-only, not DB-backed). Both land in phase E.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
