Add password reset mechanism (Issue #1)

- Added reset_token and reset_token_expiry fields to User model
- Implemented generate_reset_token(), verify_reset_token(), and clear_reset_token() methods
- Created password reset request form (/password-reset-request)
- Created password reset form (/password-reset/<token>)
- Added "Forgot password?" link to login page
- Reset tokens expire after 1 hour for security
- Created migration script to add new database columns
- Reset links are logged (would be emailed in production)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

templates/login.html

@@ -37,6 +37,10 @@
                 <label for="remember" style="margin-bottom: 0;">Remember me</label>
             </div>
 
+            <div style="text-align: right; margin-bottom: 16px;">
+                <a href="{{ url_for('password_reset_request') }}" style="color: var(--primary-color); text-decoration: none; font-size: 14px;">Forgot password?</a>
+            </div>
+
             <button type="submit">Log In</button>
         </form>