v1.6.0 — TOTP 2FA and UI polish

v1.6.0 — TOTP 2FA and UI polish

Added

• TOTP two-factor authentication for user accounts.
• Authenticator app enrollment with QR code and manual secret.
• Login challenge after password verification for users with 2FA enabled.
• Recovery codes stored as bcrypt hashes.
• 2FA disable flow protected by current password and TOTP code.

Improved

• Reworked /profile/2fa visual layout.
• Polished main page hero, quick actions and project summary.
• Fixed certificate list layout on wide and narrow screens.
• Improved certificate filters and action buttons responsiveness.

Verified

• go test ./...
• docker compose config --quiet
• Docker build and deployment check on the test server.