fix texthooker gate, overlay fallback, and control server byte limit

- gate --texthooker flag on both CLI useTexthooker arg and plugin texthookerEnabled
- remove erroneous return that blocked legacy app startup fallback after control command failure
- fix open-config-settings to only skipRender when window actually opened
- track raw byte count for accurate 64KB limit in app control server

src/main/runtime/app-control-server.ts

@@ -44,12 +44,14 @@ export function startAppControlServer(options: AppControlServerOptions): AppCont
 
   const server = net.createServer((socket) => {
     let buffer = '';
+    let byteCount = 0;
     let handled = false;
 
     socket.on('data', (chunk) => {
       if (handled) return;
+      byteCount += chunk.length;
       buffer += chunk.toString('utf8');
-      if (buffer.length > 65536) {
+      if (byteCount > 65536) {
         handled = true;
         writeResponse(socket, { ok: false, error: 'App control request too large' });
         return;