feat(FN-1754): raise global max concurrent ceiling to 10000

- Enforce 10000 upper bound in CentralCore for globalMaxConcurrent setting
- Add 10000 upper bound validation in the project settings API route
- Raise max ceiling in SettingsModal from previous limit to 10000
- Add route test verifying the 10000 upper bound is enforced

packages/core/src/central-core.ts

@@ -1748,6 +1748,13 @@ export class CentralCore extends EventEmitter<CentralCoreEvents> {
   ): Promise<GlobalConcurrencyState> {
     this.ensureInitialized();
 
+    if (
+      updates.globalMaxConcurrent !== undefined &&
+      (!Number.isFinite(updates.globalMaxConcurrent) || updates.globalMaxConcurrent < 1 || updates.globalMaxConcurrent > 10000)
+    ) {
+      throw new Error("globalMaxConcurrent must be between 1 and 10000");
+    }
+
     const current = await this.getGlobalConcurrencyState();
     const updated = {
       ...current,

packages/dashboard/app/components/SettingsModal.tsx

@@ -1545,7 +1545,7 @@ export function SettingsModal({
                 id="globalMaxConcurrent"
                 type="number"
                 min={1}
-                max={50}
+                max={10000}
                 value={globalMaxConcurrent ?? ""}
                 onChange={(e) => {
                   const val = e.target.value;

packages/dashboard/src/__tests__/project-routes.test.ts

@@ -669,6 +669,22 @@ describe("PUT /api/global-concurrency route handler", () => {
     expect(mockUpdateGlobalConcurrency).toHaveBeenCalledWith({ globalMaxConcurrent: 10 });
     expect((res.body as any).globalMaxConcurrent).toBe(10);
   });
+
+  it("rejects globalMaxConcurrent above 10000", async () => {
+    const store = new MockStoreForRoutes();
+    const app = createServer(store as any);
+
+    const res = await request(
+      app,
+      "PUT",
+      "/api/global-concurrency",
+      JSON.stringify({ globalMaxConcurrent: 10001 }),
+      { "Content-Type": "application/json" },
+    );
+
+    expect(res.status).toBe(400);
+    expect(mockUpdateGlobalConcurrency).not.toHaveBeenCalled();
+  });
 });
 
 // ── GET /api/projects/:id/health Route Tests ─────────────────────────────────

packages/dashboard/src/routes.ts

@@ -14199,8 +14199,8 @@ export function createApiRoutes(store: TaskStore, options?: ServerOptions): Rout
    */
   router.put("/global-concurrency", async (req, res) => {
     const { globalMaxConcurrent } = req.body ?? {};
-    if (!Number.isInteger(globalMaxConcurrent) || globalMaxConcurrent < 1) {
-      throw badRequest("globalMaxConcurrent must be an integer >= 1");
+    if (!Number.isInteger(globalMaxConcurrent) || globalMaxConcurrent < 1 || globalMaxConcurrent > 10000) {
+      throw badRequest("globalMaxConcurrent must be an integer between 1 and 10000");
     }
 
     try {