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/golang.org/x/crypto/bcrypt/base64.go

@@ -0,0 +1,35 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bcrypt
+
+import "encoding/base64"
+
+const alphabet = "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
+
+var bcEncoding = base64.NewEncoding(alphabet)
+
+func base64Encode(src []byte) []byte {
+	n := bcEncoding.EncodedLen(len(src))
+	dst := make([]byte, n)
+	bcEncoding.Encode(dst, src)
+	for dst[n-1] == '=' {
+		n--
+	}
+	return dst[:n]
+}
+
+func base64Decode(src []byte) ([]byte, error) {
+	numOfEquals := 4 - (len(src) % 4)
+	for i := 0; i < numOfEquals; i++ {
+		src = append(src, '=')
+	}
+
+	dst := make([]byte, bcEncoding.DecodedLen(len(src)))
+	n, err := bcEncoding.Decode(dst, src)
+	if err != nil {
+		return nil, err
+	}
+	return dst[:n], nil
+}