Epic: Authentication — Login Feature

[ElbekDeveloper]

Epic: Authentication

Full login feature broken into 4 specs following SDD workflow.

Child Issues

• Epic: Authentication — Login Feature #1 — Auth library setup
• feat: Auth library & project setup #2 — Shared UI components
• feat: Shared UI component library (button, input, spinner) #3 — Login page (frontend only)
• feat: Login page — frontend form, routing, no backend #4 — Backend integration (REST + HttpOnly JWT)

Constitution ref: Principle I (SDD), Principle II (Signals), Principle III (AXE)