chore: add ESLint v9 config with typescript-eslint

- Add eslint.config.mjs with typescript-eslint integration
- Install typescript-eslint, @typescript-eslint/eslint-plugin, @typescript-eslint/parser
- Fix unused params warning in ipc-handlers.ts

src/main/ipc-handlers.ts

@@ -531,7 +531,7 @@ function registerDeleteVersion(): void {
  * Rollback to a previous version
  */
 function registerRollback(): void {
-  handleWithParams<RollbackParams, DeployResult>("rollback", async (params) => {
+  handleWithParams<RollbackParams, DeployResult>("rollback", async (_params) => {
     // This would read the version file and redeploy
     // Simplified implementation - would need full implementation
     throw new Error("Rollback not yet implemented");