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

vendor/github.com/jackc/puddle/v2/nanotime.go

@@ -0,0 +1,16 @@
+package puddle
+
+import "time"
+
+// nanotime returns the time in nanoseconds since process start.
+//
+// This approach, described at
+// https://github.com/golang/go/issues/61765#issuecomment-1672090302,
+// is fast, monotonic, and portable, and avoids the previous
+// dependence on runtime.nanotime using the (unsafe) linkname hack.
+// In particular, time.Since does less work than time.Now.
+func nanotime() int64 {
+	return time.Since(globalStart).Nanoseconds()
+}
+
+var globalStart = time.Now()