fix: resolve linting errors

- Remove duplicate node:path import in test/icon-validation.test.ts
- Replace 4 instances of 'any' type with 'unknown' in error handlers
- Auto-format code with prettier (27 formatting fixes)

Addresses review feedback from PR #136
All 6 errors and 27 warnings resolved

src/node/validate.ts

@@ -59,7 +59,7 @@ function validateIcon(
   // Check for ${__dirname} variable (error - doesn't work)
   if (hasVariableSubstitution) {
     errors.push(
-      'Icon path should not use ${__dirname} variable substitution. ' +
+      "Icon path should not use ${__dirname} variable substitution. " +
         'Use a simple relative path like "icon.png" instead of "${__dirname}/icon.png".',
     );
   }