feat(utils): add version retrieval utility

- Introduces a function to retrieve the application version
- Returns 'dev' if the version file is missing and 'unknown' for other errors
- Exports the new utility for use in other modules

src/utils/mod.ts

@@ -1,2 +1,3 @@
 export { resolveUnitTargetPath, writeUnitFiles } from './fs.ts';
 export { deriveNameFromExec } from './misc.ts';
+export { getVersion } from './version.ts';

src/utils/version.ts

@@ -0,0 +1,12 @@
+export async function getVersion(): Promise<string> {
+    try {
+        const versionUrl = new URL('../../VERSION', import.meta.url);
+        const version = await Deno.readTextFile(versionUrl);
+        return version.trim();
+    } catch (err) {
+        if (err instanceof Deno.errors.NotFound) {
+            return 'dev';
+        }
+        return 'unknown';
+    }
+}