Initial commit: Lookbook personal collection app

Pinterest-like app for saving images, videos, quotes, and embeds.

Features:
- Go backend with PostgreSQL, SSR templates
- Console-based admin auth (login/logout via browser console)
- Item types: images, videos (ffmpeg transcoding), quotes, embeds
- Media stored as BLOBs in PostgreSQL
- OpenGraph metadata extraction for links
- Embed detection for YouTube, Vimeo, Twitter/X
- Masonry grid layout, item detail pages
- Tag system with filtering
- Refresh metadata endpoint with change warnings
- Replace media endpoint for updating item images/videos

internal/handlers/handler.go

@@ -0,0 +1,49 @@
+package handlers
+
+import (
+	"log/slog"
+	"net/http"
+)
+
+// Handler is a function that handles HTTP requests and can return an error.
+// It receives a RequestContext with injected dependencies (DB, Logger).
+type Handler func(rc *RequestContext, w http.ResponseWriter, r *http.Request) error
+
+// WithErrorHandling wraps a Handler to automatically handle errors.
+func WithErrorHandling(rc *RequestContext, h Handler) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		wrapper := &responseWrapper{
+			ResponseWriter: w,
+			written:        false,
+		}
+
+		err := h(rc, wrapper, r)
+		if err != nil {
+			rc.Logger.Error("handler error",
+				slog.String("method", r.Method),
+				slog.String("path", r.URL.Path),
+				slog.Any("error", err),
+			)
+
+			if !wrapper.written {
+				http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+			}
+		}
+	}
+}
+
+// responseWrapper tracks if response was written
+type responseWrapper struct {
+	http.ResponseWriter
+	written bool
+}
+
+func (w *responseWrapper) Write(b []byte) (int, error) {
+	w.written = true
+	return w.ResponseWriter.Write(b)
+}
+
+func (w *responseWrapper) WriteHeader(statusCode int) {
+	w.written = true
+	w.ResponseWriter.WriteHeader(statusCode)
+}