fix: parse JSON bodies for /api/provider routes

Custom provider upsert uses PUT /api/provider, which was skipped by the
selective express.json allowlist and always saw an empty body.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

packages/web/server/lib/opencode/core-routes.js

@@ -1070,6 +1070,7 @@ export const registerCommonRequestMiddleware = (app, dependencies) => {
       req.path.startsWith('/api/push') ||
       req.path.startsWith('/api/notifications') ||
       req.path.startsWith('/api/permission-auto-accept') ||
+      req.path.startsWith('/api/provider') ||
       req.path.startsWith('/api/session-folders') ||
       req.path.startsWith('/api/small-model') ||
       req.path.startsWith('/api/goals') ||