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/pgx/v5/values.go

@@ -0,0 +1,63 @@
+package pgx
+
+import (
+	"errors"
+
+	"github.com/jackc/pgx/v5/internal/pgio"
+	"github.com/jackc/pgx/v5/pgtype"
+)
+
+// PostgreSQL format codes
+const (
+	TextFormatCode   = 0
+	BinaryFormatCode = 1
+)
+
+func convertSimpleArgument(m *pgtype.Map, arg any) (any, error) {
+	buf, err := m.Encode(0, TextFormatCode, arg, []byte{})
+	if err != nil {
+		return nil, err
+	}
+	if buf == nil {
+		return nil, nil
+	}
+	return string(buf), nil
+}
+
+func encodeCopyValue(m *pgtype.Map, buf []byte, oid uint32, arg any) ([]byte, error) {
+	sp := len(buf)
+	buf = pgio.AppendInt32(buf, -1)
+	argBuf, err := m.Encode(oid, BinaryFormatCode, arg, buf)
+	if err != nil {
+		if argBuf2, err2 := tryScanStringCopyValueThenEncode(m, buf, oid, arg); err2 == nil {
+			argBuf = argBuf2
+		} else {
+			return nil, err
+		}
+	}
+
+	if argBuf != nil {
+		buf = argBuf
+		pgio.SetInt32(buf[sp:], int32(len(buf[sp:])-4))
+	}
+	return buf, nil
+}
+
+func tryScanStringCopyValueThenEncode(m *pgtype.Map, buf []byte, oid uint32, arg any) ([]byte, error) {
+	s, ok := arg.(string)
+	if !ok {
+		textBuf, err := m.Encode(oid, TextFormatCode, arg, nil)
+		if err != nil {
+			return nil, errors.New("not a string and cannot be encoded as text")
+		}
+		s = string(textBuf)
+	}
+
+	var v any
+	err := m.Scan(oid, TextFormatCode, []byte(s), &v)
+	if err != nil {
+		return nil, err
+	}
+
+	return m.Encode(oid, BinaryFormatCode, v, buf)
+}