Initial lookbook implementation

Pinterest-style visual bookmarking app with:
- URL metadata extraction (OG/Twitter meta, oEmbed fallback)
- Image caching in Postgres with 480px thumbnails
- Multi-tag filtering with Ctrl/Cmd for OR mode
- Fuzzy tag suggestions and inline tag editing
- Browser console auth() with first-use password setup
- Brutalist UI with Commit Mono font and Pico CSS
- Light/dark mode via browser preference

internal/handlers/auth.go

@@ -0,0 +1,167 @@
+package handlers
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+
+	"golang.org/x/crypto/bcrypt"
+
+	"git.soup.land/soup/lookbook/internal/data/auth"
+	"git.soup.land/soup/lookbook/internal/data/session"
+)
+
+const sessionCookieName = "lookbook_session"
+const sessionDuration = 30 * 24 * time.Hour
+
+type authRequest struct {
+	Password string `json:"password"`
+}
+
+type authStatus struct {
+	Authenticated bool `json:"authenticated"`
+	HasPassword   bool `json:"has_password"`
+}
+
+func HandlePostAuthLogin(rc *RequestContext, w http.ResponseWriter, r *http.Request) error {
+	var req authRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		http.Error(w, "Invalid request", http.StatusBadRequest)
+		return nil
+	}
+	if req.Password == "" {
+		http.Error(w, "Password required", http.StatusBadRequest)
+		return nil
+	}
+
+	existing, err := auth.QGet(r.Context(), rc.DB)
+	if err != nil {
+		return fmt.Errorf("get auth: %w", err)
+	}
+
+	if existing == nil {
+		hash, err := bcrypt.GenerateFromPassword([]byte(req.Password), bcrypt.DefaultCost)
+		if err != nil {
+			return fmt.Errorf("hash password: %w", err)
+		}
+		if _, err := auth.QCreate(r.Context(), rc.DB, hash); err != nil {
+			return fmt.Errorf("create password: %w", err)
+		}
+	} else {
+		if err := bcrypt.CompareHashAndPassword(existing.PasswordHash, []byte(req.Password)); err != nil {
+			http.Error(w, "Unauthorized", http.StatusUnauthorized)
+			return nil
+		}
+	}
+
+	token, err := newToken(32)
+	if err != nil {
+		return fmt.Errorf("token: %w", err)
+	}
+
+	expiresAt := time.Now().Add(sessionDuration)
+	if _, err := session.QCreate(r.Context(), rc.DB, token, expiresAt); err != nil {
+		return fmt.Errorf("create session: %w", err)
+	}
+
+	setSessionCookie(w, r, token, expiresAt)
+	w.WriteHeader(http.StatusNoContent)
+	return nil
+}
+
+func HandlePostAuthLogout(rc *RequestContext, w http.ResponseWriter, r *http.Request) error {
+	cookie, err := r.Cookie(sessionCookieName)
+	if err == nil {
+		_ = session.QDelete(r.Context(), rc.DB, cookie.Value)
+	}
+	clearSessionCookie(w, r)
+	w.WriteHeader(http.StatusNoContent)
+	return nil
+}
+
+func HandleGetAuthStatus(rc *RequestContext, w http.ResponseWriter, r *http.Request) error {
+	status := authStatus{}
+
+	existing, err := auth.QGet(r.Context(), rc.DB)
+	if err != nil {
+		return fmt.Errorf("get auth: %w", err)
+	}
+	status.HasPassword = existing != nil
+
+	authed, err := isAuthenticated(r, rc)
+	if err != nil {
+		return fmt.Errorf("auth status: %w", err)
+	}
+	status.Authenticated = authed
+
+	w.Header().Set("Content-Type", "application/json")
+	return json.NewEncoder(w).Encode(status)
+}
+
+func isAuthenticated(r *http.Request, rc *RequestContext) (bool, error) {
+	cookie, err := r.Cookie(sessionCookieName)
+	if err != nil {
+		return false, nil
+	}
+
+	row, err := session.QFindByToken(r.Context(), rc.DB, cookie.Value)
+	if err != nil {
+		return false, err
+	}
+	if row == nil {
+		return false, nil
+	}
+	if time.Now().After(row.ExpiresAt) {
+		_ = session.QDelete(r.Context(), rc.DB, cookie.Value)
+		return false, nil
+	}
+	return true, nil
+}
+
+func requireAuth(w http.ResponseWriter, r *http.Request, rc *RequestContext) bool {
+	authed, err := isAuthenticated(r, rc)
+	if err != nil {
+		http.Error(w, "Unauthorized", http.StatusUnauthorized)
+		return false
+	}
+	if !authed {
+		http.Error(w, "Unauthorized", http.StatusUnauthorized)
+		return false
+	}
+	return true
+}
+
+func setSessionCookie(w http.ResponseWriter, r *http.Request, token string, expiresAt time.Time) {
+	http.SetCookie(w, &http.Cookie{
+		Name:     sessionCookieName,
+		Value:    token,
+		Path:     "/",
+		HttpOnly: true,
+		Secure:   r.TLS != nil,
+		SameSite: http.SameSiteLaxMode,
+		Expires:  expiresAt,
+	})
+}
+
+func clearSessionCookie(w http.ResponseWriter, r *http.Request) {
+	http.SetCookie(w, &http.Cookie{
+		Name:     sessionCookieName,
+		Value:    "",
+		Path:     "/",
+		HttpOnly: true,
+		Secure:   r.TLS != nil,
+		SameSite: http.SameSiteLaxMode,
+		Expires:  time.Unix(0, 0),
+	})
+}
+
+func newToken(length int) (string, error) {
+	buf := make([]byte, length)
+	if _, err := rand.Read(buf); err != nil {
+		return "", err
+	}
+	return base64.RawURLEncoding.EncodeToString(buf), nil
+}