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

shell.nix

@@ -0,0 +1,15 @@
+let
+	pins = import ./npins;
+	sx-nix = import ../sx-nix {};
+	pkgs = sx-nix.pkgs;
+in
+
+pkgs.mkShell {
+	packages = [
+		(sx-nix.go.goToolchainBin { version = "1.25.5"; sha256 = "sha256-npt1XWOzas8wwSqaP8N5JDcUwcbT3XKGHaY38zbrs1s="; })
+		pkgs.postgresql
+		pkgs.entr
+		pkgs.fd
+		pkgs.hivemind
+	];
+}