diff --git a/internal/api/src/routes/files.server.ts b/internal/api/src/routes/files.server.ts
index edb6a8b8..640144f0 100644
--- a/internal/api/src/routes/files.server.ts
+++ b/internal/api/src/routes/files.server.ts
@@ -49,8 +49,10 @@ export default function mountFiles(server: APIServer) {
     // Note: this happens with createServer from node:http, not with Bun.serve.
     return c.body(file.stream, 200, {
       "Content-Type": file.type,
-      // Inline to prevent the browser from downloading the file.
       "Content-Disposition": `inline; filename="${file.name}"`,
+      "X-Content-Type-Options": "nosniff",
+      "Content-Security-Policy":
+        "default-src 'none'; sandbox; frame-ancestors 'none'",
     });
   });
 }
diff --git a/internal/api/src/routes/files.test.ts b/internal/api/src/routes/files.test.ts
index 11eff827..5280524d 100644
--- a/internal/api/src/routes/files.test.ts
+++ b/internal/api/src/routes/files.test.ts
@@ -3,7 +3,7 @@ import { serve } from "../test";
 
 test("POST+GET /api/files", async () => {
   const { helpers } = await serve();
-  const { client, user } = await helpers.createUser();
+  const { client } = await helpers.createUser();
   const file = new File(["Hello, world!"], "test.txt");
   const resp = await client.files.upload(file);
   expect(resp.id).toBeString();
@@ -12,3 +12,27 @@ test("POST+GET /api/files", async () => {
   const fileResp = await client.files.get(resp.id);
   expect(await fileResp.text()).toBe("Hello, world!");
 });
+
+test("GET /api/files serves uploaded files inline with restrictive headers", async () => {
+  const { helpers } = await serve();
+  const { client } = await helpers.createUser();
+  const file = new File(["<h1>content</h1>"], "content.html", {
+    type: "text/html",
+  });
+
+  const uploaded = await client.files.upload(file);
+  const response = await fetch(uploaded.url);
+
+  expect(response.status).toBe(200);
+  expect(await response.text()).toBe("<h1>content</h1>");
+  expect(response.headers.get("content-type")).toStartWith("text/html");
+  expect(response.headers.get("content-disposition")).toBe(
+    'inline; filename="content.html"'
+  );
+  expect(response.headers.get("x-content-type-options")).toBe("nosniff");
+  const csp = response.headers.get("content-security-policy");
+  expect(csp).toContain("default-src 'none'");
+  expect(csp).toContain("sandbox");
+  expect(csp).toContain("frame-ancestors 'none'");
+  expect(response.headers.get("x-frame-options")).toBeNull();
+});
diff --git a/internal/database/src/postgres-worker.ts b/internal/database/src/postgres-worker.ts
index 5542fdbe..ecf1f8e5 100644
--- a/internal/database/src/postgres-worker.ts
+++ b/internal/database/src/postgres-worker.ts
@@ -506,6 +506,7 @@ self.onmessage = async (e) => {
       },
       async onMessage(data, { isAuthenticated }) {
         if (!isAuthenticated) return;
+        if (data[0] === FrontendMessageCode.Terminate) return;
         maybeClaimOnEnqueue(socket, data);
         return new Promise<Uint8Array>((resolve, reject) => {
           taskQueue.push({ socket, data, resolve, reject });
@@ -519,9 +520,12 @@ self.onmessage = async (e) => {
     const cleanupSocket = () => {
       releaseOwnerIf(socket);
       for (let i = taskQueue.length - 1; i >= 0; i--) {
-        if (taskQueue[i]!.socket === socket) {
+        const task = taskQueue[i];
+        if (task?.socket === socket) {
           try {
-            taskQueue[i]!.reject(new Error("Socket closed"));
+            // Closed sockets cannot receive pending responses, so complete
+            // queued work without producing an error.
+            task.resolve(new Uint8Array(0));
           } catch {}
           taskQueue.splice(i, 1);
         }
diff --git a/internal/site/components/chat-message-input.test.tsx b/internal/site/components/chat-message-input.test.tsx
index 8d48d97f..87c75446 100644
--- a/internal/site/components/chat-message-input.test.tsx
+++ b/internal/site/components/chat-message-input.test.tsx
@@ -1,5 +1,7 @@
-import { render, waitFor } from "@testing-library/react";
+// Load the core package first so Bun initializes Lexical's shared exports before @lexical/react.
+import "lexical";
 import { afterAll, beforeAll, expect, test } from "bun:test";
+import { render, waitFor } from "@testing-library/react";
 import { Window } from "happy-dom";
 import {
   ChatMessageInput,
@@ -14,13 +16,13 @@ beforeAll(() => {
 });
 
 afterAll(async () => {
-  // @ts-ignore
+  // @ts-expect-error
   delete globalThis.window;
-  // @ts-ignore
+  // @ts-expect-error
   delete globalThis.document;
-  // @ts-ignore
+  // @ts-expect-error
   delete globalThis.MutationObserver;
-  // @ts-ignore
+  // @ts-expect-error
   delete globalThis.getComputedStyle;
 });
 
diff --git a/internal/site/components/chat-multimodal-input.test.tsx b/internal/site/components/chat-multimodal-input.test.tsx
index eca8381f..a112562a 100644
--- a/internal/site/components/chat-multimodal-input.test.tsx
+++ b/internal/site/components/chat-multimodal-input.test.tsx
@@ -1,7 +1,9 @@
-import type { UIAttachment } from "@/hooks/use-attachments";
-import { fireEvent, render, waitFor } from "@testing-library/react";
+// Load the core package first so Bun initializes Lexical's shared exports before @lexical/react.
+import "lexical";
 import { afterAll, beforeAll, expect, mock, test } from "bun:test";
+import { fireEvent, render, waitFor } from "@testing-library/react";
 import { Window } from "happy-dom";
+import type { UIAttachment } from "@/hooks/use-attachments";
 import type { ChatMessageInputRef } from "./chat-message-input";
 import {
   ChatMultimodalInput,
@@ -17,13 +19,13 @@ beforeAll(() => {
 });
 
 afterAll(async () => {
-  // @ts-ignore
+  // @ts-expect-error
   delete globalThis.window;
-  // @ts-ignore
+  // @ts-expect-error
   delete globalThis.document;
-  // @ts-ignore
+  // @ts-expect-error
   delete globalThis.MutationObserver;
-  // @ts-ignore
+  // @ts-expect-error
   delete globalThis.getComputedStyle;
 });