feat: remove legacy OpenCode runtime

Cut product flows over to Coding/Pi and retain only the migration-owned v1 boundary. Promote supported native optional packages because electron-builder omitted pnpm transitive optional closure from the packaged ASAR.

electron/api/server.ts

@@ -33,7 +33,7 @@ export function startHostApiServer(ctx: HostApiContext, port = getPort('NIANCODE
       // Set origin-aware CORS headers early so every response
       // (including error responses) carries them consistently.
       const origin = req.headers.origin;
-      setCorsHeaders(res, origin, ctx.opencodeManager.getStatus().url);
+      setCorsHeaders(res, origin);
 
       // CORS preflight — respond before auth so browsers can negotiate.
       if (req.method === 'OPTIONS') {