refactor: migrate shiki to core API with dynamic language/theme loading

- Update code block regex to support symbols/numbers in language identifiers
- Adjust codespan background color to a softer shade

index.ts

@@ -15,6 +15,7 @@ const { values: args, positionals } = parseArgs({
     n: { type: "boolean" },
     config: { type: "boolean" },
     c: { type: "boolean" },
+    v: { type: "boolean" },
     plain: { type: "boolean" },
     plainOut: { type: "boolean" },
     plainErr: { type: "boolean" },
@@ -30,6 +31,11 @@ async function main() {
   const modelFlag = args.model ?? args.m;
   const configFlag = args.config ?? args.c;
 
+  if (args.v) {
+    console.log("0.0.0");
+    return;
+  }
+
   const config = await loadConfig(configFlag);
 
   if (configFlag || !config) {