feat: initialize k-tv-frontend with Next.js and Tailwind CSS

- Added package.json with dependencies and scripts for development, build, and linting.
- Created postcss.config.mjs for Tailwind CSS integration.
- Added SVG assets for UI components including file, globe, next, vercel, and window icons.
- Configured TypeScript with tsconfig.json for strict type checking and module resolution.

k-tv-backend/migrations_sqlite/20240101000000_init_users.sql

@@ -0,0 +1,11 @@
+-- Create users table
+CREATE TABLE IF NOT EXISTS users (
+    id TEXT PRIMARY KEY NOT NULL,
+    subject TEXT NOT NULL,
+    email TEXT NOT NULL,
+    password_hash TEXT,
+    created_at TEXT NOT NULL
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS idx_users_subject ON users(subject);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_users_email ON users(email);