build(treefmt): replace prettier with oxfmt

Migrate from prettier to oxfmt for formatting non-Python files.
oxfmt is part of the oxc project and provides faster formatting
with native Rust implementation.

Changes:
- Remove prettier configuration from treefmt programs
- Add oxfmt as custom formatter with explicit includes
- Extend supported file types: md, yml, yaml, json, ts, tsx, js, jsx, html, css
- Update flake.lock with latest nixpkgs containing oxfmt

Author: ryoppippi

flake.lock

@@ -42,20 +42,26 @@
               nixfmt.package = pkgs.nixfmt-rfc-style;
               ruff-check.enable = true;
               ruff-format.enable = true;
-              prettier = {
-                enable = true;
-                includes = [
-                  "*.md"
-                  "*.yml"
-                  "*.yaml"
-                  "*.json"
-                ];
-                excludes = [
-                  "CHANGELOG.md"
-                ];
-              };
               typos.enable = true;
             };
+            settings.formatter.oxfmt = {
+              command = "${pkgs.oxfmt}/bin/oxfmt";
+              includes = [
+                "*.md"
+                "*.yml"
+                "*.yaml"
+                "*.json"
+                "*.ts"
+                "*.tsx"
+                "*.js"
+                "*.jsx"
+                "*.html"
+                "*.css"
+              ];
+              excludes = [
+                "CHANGELOG.md"
+              ];
+            };
           };
 
           # Git hooks configuration