feat(auth): extend session duration to 7 days using constants

- Add SessionDuration constant (7 days) and SessionDurationSec computed value
- Update JWT token expiration to use SessionDuration instead of 1 hour
- Update register/login cookie MaxAge to use SessionDurationSec (604800)
- Update register/login API response ExpiresIn to use SessionDurationSec
- Update refresh token endpoint ExpiresIn to use SessionDurationSec
- Remove redundant client-side document.cookie lines from login/register
- Add TODO comment for HTTPS cookie Secure flag

This provides Google-like persistent sessions with a single source of truth
for session duration, eliminating hardcoded values throughout the codebase.

internal/handlers/auth.go

@@ -18,6 +18,16 @@ import (
 	"golang.org/x/crypto/bcrypt"
 )
 
+const (
+	// Session duration constants
+	// Follows same pattern as refresh_token.go
+	SessionDuration = 7 * 24 * time.Hour // 7 days
+)
+
+// SessionDurationSec is the session duration in seconds for use in cookies and API responses
+// Note: This is computed from SessionDuration to avoid magic numbers
+var SessionDurationSec = int(SessionDuration.Seconds())
+
 type AuthHandler struct {
 	db                  *database.Queries
 	jwtKey              []byte
@@ -219,8 +229,8 @@ func (h *AuthHandler) Register(c echo.Context) error {
 		Value:    accessToken,
 		Path:     "/",
 		HttpOnly: true,
-		Secure:   false,
-		MaxAge:   3600,
+		Secure:   false, // TODO: Set to true in production with HTTPS
+		MaxAge:   SessionDurationSec,
 	}
 	c.SetCookie(cookie)
 
@@ -238,9 +248,8 @@ func (h *AuthHandler) Register(c echo.Context) error {
 localStorage.setItem('token', '%s');
 localStorage.setItem('refreshToken', '%s');
 localStorage.setItem('user', JSON.stringify(%s));
-document.cookie = 'token=%s; path=/; max-age=3600';
 window.location.href = '/dashboard';
-</script>`, accessToken, refreshToken, fmt.Sprintf(`{"id":"%s","email":"%s","username":"%s"}`, uuid.UUID(user.ID.Bytes).String(), user.Email, user.Username), accessToken)
+</script>`, accessToken, refreshToken, fmt.Sprintf(`{"id":"%s","email":"%s","username":"%s"}`, uuid.UUID(user.ID.Bytes).String(), user.Email, user.Username))
 		return c.HTML(http.StatusCreated, html)
 	}
 
@@ -254,7 +263,7 @@ window.location.href = '/dashboard';
 		Token:        accessToken,
 		RefreshToken: refreshToken,
 		TokenType:    "Bearer",
-		ExpiresIn:    3600,
+		ExpiresIn:    SessionDurationSec,
 		User: UserProfile{
 			ID:        uuid.UUID(user.ID.Bytes).String(),
 			Email:     user.Email,
@@ -365,8 +374,8 @@ func (h *AuthHandler) Login(c echo.Context) error {
 		Value:    accessToken,
 		Path:     "/",
 		HttpOnly: true,
-		Secure:   false,
-		MaxAge:   3600,
+		Secure:   false, // TODO: Set to true in production with HTTPS
+		MaxAge:   SessionDurationSec,
 	}
 	c.SetCookie(cookie)
 
@@ -388,9 +397,8 @@ func (h *AuthHandler) Login(c echo.Context) error {
 localStorage.setItem('token', '%s');
 localStorage.setItem('refreshToken', '%s');
 localStorage.setItem('user', JSON.stringify(%s));
-document.cookie = 'token=%s; path=/; max-age=3600';
 window.location.href = '%s';
-</script>`, accessToken, refreshToken, fmt.Sprintf(`{"id":"%s","email":"%s","username":"%s","first_name":"%s","last_name":"%s"}`, uuid.UUID(user.ID.Bytes).String(), user.Email, user.Username, user.FirstName.String, user.LastName.String), accessToken, redirect)
+</script>`, accessToken, refreshToken, fmt.Sprintf(`{"id":"%s","email":"%s","username":"%s","first_name":"%s","last_name":"%s"}`, uuid.UUID(user.ID.Bytes).String(), user.Email, user.Username, user.FirstName.String, user.LastName.String), redirect)
 		return c.HTML(http.StatusOK, html)
 	}
 
@@ -406,7 +414,7 @@ window.location.href = '%s';
 		Token:        accessToken,
 		RefreshToken: refreshToken,
 		TokenType:    "Bearer",
-		ExpiresIn:    3600,
+		ExpiresIn:    SessionDurationSec,
 		User: UserProfile{
 			ID:        uuid.UUID(user.ID.Bytes).String(),
 			Email:     user.Email,
@@ -780,7 +788,7 @@ func (h *AuthHandler) generateJWTWithAllClaims(userID, userRole, userEmail, user
 		"user_role":     userRole,
 		"user_email":    userEmail,
 		"user_username": userUsername,
-		"exp":           time.Now().Add(1 * time.Hour).Unix(),
+		"exp":           time.Now().Add(SessionDuration).Unix(),
 		"iat":           time.Now().Unix(),
 	}
 	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)