v26.10.5 (#1710)

* feat: add an auto or fixed columns picker to card grids

* feat: add safe mode that only runs layout and theme plugins

* docs: add simple layout to plugin table

* fix: ask for local network access in the macOS app

* feat: allow plugin registries on listed private hosts (#1705)

* chore: add private registry hosts to the changelog

* feat: use the proxy for plugin registry downloads

* fix: allow changing connection origin on shared hosts

* chore: update translations and plugin pins

* chore: lint, format, and bump version to 26.10.5

---------

Co-authored-by: Lukas <80832688+0skater0@users.noreply.github.com>

src/backend/database/routes/look.ts

@@ -18,6 +18,7 @@ import {
   safeLayoutForced,
   unavailableLooks,
 } from "../../plugins/looks.js";
+import { safeModeOn } from "../../plugins/safe-mode.js";
 
 const router = express.Router();
 const authManager = AuthManager.getInstance();
@@ -36,7 +37,7 @@ async function adminDefaults() {
  * /user-preferences/look:
  *   get:
  *     summary: Get the layout and theme to show the current user
- *     description: The user's own choice, the admin defaults (a layout no installed plugin brings reads as null), the default look of the bundled plugins, whether TERMIX_SAFE_LAYOUT forces the repair view, and installed layout or theme plugins that could not load. The browser resolves the final look from these.
+ *     description: The user's own choice, the admin defaults (a layout no installed plugin brings reads as null), the default look of the bundled plugins, whether TERMIX_SAFE_LAYOUT forces the repair view, whether TERMIX_SAFE_MODE runs only layout and theme plugins, and installed layout or theme plugins that could not load. The browser resolves the final look from these.
  *     tags:
  *       - User Preferences
  *     responses:
@@ -75,6 +76,8 @@ async function adminDefaults() {
  *                       nullable: true
  *                 safeLayout:
  *                   type: boolean
+ *                 safeMode:
+ *                   type: boolean
  *                 unavailable:
  *                   type: array
  *                   items:
@@ -112,6 +115,7 @@ router.get("/", authenticateJWT, async (req: Request, res: Response) => {
       defaults: { ...defaults, layout: known(defaults.layout) },
       defaultLook: resolveDefaultLook(loader),
       safeLayout: safeLayoutForced(),
+      safeMode: safeModeOn(),
       unavailable: unavailableLooks(loader),
     });
   } catch (error) {

src/backend/database/routes/plugins.ts

@@ -16,6 +16,7 @@ import { getPluginRuntime } from "../../plugins/index.js";
 import { resolvePluginDesktopMode } from "@termix-ssh/plugin-sdk/manifest";
 import { describePluginFrontend } from "../../plugins/assets.js";
 import { isDefaultLookPlugin } from "../../plugins/bundled-index.js";
+import { mayRunInSafeMode } from "../../plugins/safe-mode.js";
 import { invalidatePluginPermissionCache } from "../../plugins/permissions.js";
 import { getPluginPublicHttpRoutes } from "../../plugins/http.js";
 import { getPluginPublicWsRoutes } from "../../plugins/ws.js";
@@ -249,6 +250,9 @@ export async function listPreLoginPlugins(): Promise<
  *       only run on that server and stay off here on purpose, and, for
  *       admins, `managedByServer` marks plugins whose on/off state the server
  *       decides.
+ *
+ *       While TERMIX_SAFE_MODE is on, an enabled plugin that safe mode keeps
+ *       off reports `state: "safe-mode"`.
  *     tags:
  *       - Plugins
  *     responses:
@@ -354,7 +358,12 @@ router.get("/", authenticateJWT, async (req: Request, res: Response) => {
           name: record.name,
           version: record.version,
           enabled: record.state === "enabled",
-          state: loaded?.state ?? record.state,
+          state:
+            record.state === "enabled" &&
+            loaded?.state !== "active" &&
+            !mayRunInSafeMode(record.id, loader.list())
+              ? "safe-mode"
+              : (loaded?.state ?? record.state),
           runsOnServer: linked && desktopMode === "server",
           contributes,
           icon,
@@ -936,7 +945,7 @@ router.delete(
  *       404:
  *         description: No such plugin.
  *       409:
- *         description: This desktop is linked to a server, which decides whether the plugin runs.
+ *         description: This desktop is linked to a server, which decides whether the plugin runs, or safe mode is on and the plugin is not a layout or theme.
  */
 router.patch(
   "/:id/state",
@@ -1050,6 +1059,8 @@ router.patch(
  *         description: The caller lacks admin.plugins.manage.
  *       404:
  *         description: No such plugin, or it is not on disk.
+ *       409:
+ *         description: Safe mode is on and the plugin is not a layout or theme.
  *       500:
  *         description: The plugin failed to start again.
  */
@@ -1073,6 +1084,13 @@ router.post(
         res.status(404).json({ error: "Plugin is not present on disk" });
         return;
       }
+      if (!mayRunInSafeMode(pluginId, loader.list())) {
+        res.status(409).json({
+          error: "Safe mode is on, so only layout and theme plugins can start",
+          code: "SAFE_MODE",
+        });
+        return;
+      }
 
       await repository.update(pluginId, {
         state: "enabled",

src/backend/plugins/boot-state.ts

@@ -14,3 +14,24 @@ export function startablePluginIds(
       .map((record) => record.id),
   );
 }
+
+/**
+ * Plugins that shipped in an earlier image and were left on, but whose code is
+ * not in this one (a smaller image tag). They get fetched from the registry.
+ */
+export function missingShippedPluginIds(
+  records: { id: string; tier: string; state: string }[],
+  presentIds: ReadonlySet<string>,
+  ignored: ReadonlySet<string>,
+): string[] {
+  return records
+    .filter(
+      (record) =>
+        record.tier === "bundled" &&
+        record.state !== "disabled" &&
+        !presentIds.has(record.id) &&
+        !ignored.has(record.id),
+    )
+    .map((record) => record.id)
+    .sort();
+}

src/backend/plugins/index.ts

@@ -23,6 +23,11 @@ import { setHostProtocolSource } from "../hosts/protocol-auth/registry.js";
 import { setSecretResolverOwnerSource } from "../hosts/connect/secret-resolver-registry.js";
 import { recordConflict } from "./conflicts.js";
 import { startablePluginIds } from "./boot-state.js";
+import {
+  mayRunInSafeMode,
+  safeModeOn,
+  safeModePluginIds,
+} from "./safe-mode.js";
 import { setPluginImpersonationCheck } from "../utils/auth-manager.js";
 import { setKeybindingActionSource } from "../database/routes/keybinding-validation.js";
 
@@ -237,6 +242,10 @@ export async function initializePlugins(
   if (loaded.length === 0) return [];
 
   const fresh = await seedPlugins(loaded, options.freshInstall === true);
+  if (!fresh) {
+    const { restoreMissingPlugins } = await import("./manage.js");
+    loaded.push(...(await restoreMissingPlugins()));
+  }
   await syncCapabilityGrants(loaded);
   if (loaded.some((plugin) => plugin.source === "bundled")) {
     const { offerPluginSetup } = await import("./onboarding.js");
@@ -248,8 +257,17 @@ export async function initializePlugins(
   const records = await createCurrentPluginRepository().listAll();
   const enabled = startablePluginIds(records);
 
+  const safe = safeModeOn() ? safeModePluginIds(loaded) : null;
+  if (safe) {
+    pluginLogger.warn(
+      "Safe mode is on (TERMIX_SAFE_MODE). Only layout and theme plugins start",
+      { operation: "plugin_init" },
+    );
+  }
+
   const candidates = loaded
     .filter((plugin) => enabled.has(plugin.id))
+    .filter((plugin) => !safe || safe.has(plugin.id))
     .map((plugin) => plugin.id);
 
   for (const pluginId of candidates) {
@@ -539,6 +557,8 @@ export async function activatePlugin(pluginId: string): Promise<void> {
   // Before activate: a plugin's own activate() may already want to check one
   // of its permissions.
   const plugin = pluginLoader.get(pluginId);
+  // Stays enabled and starts on the next boot without safe mode.
+  if (!mayRunInSafeMode(pluginId, pluginLoader.list())) return;
   if (plugin) await registerPluginPermissions(plugin);
 
   await pluginLoader.activate(pluginId);

src/backend/plugins/manage.ts

@@ -18,6 +18,7 @@ import path from "node:path";
 import semver from "semver";
 import { pluginLogger } from "../utils/logger.js";
 import { isDefaultLookPlugin } from "./bundled-index.js";
+import { mayRunInSafeMode } from "./safe-mode.js";
 import {
   activatePlugin,
   deactivatePlugin,
@@ -25,6 +26,7 @@ import {
   registerLoadedPlugins,
   unloadPlugin,
 } from "./index.js";
+import { missingShippedPluginIds } from "./boot-state.js";
 import type { LoadedPlugin, PluginLoader } from "./loader.js";
 import {
   getBundledPluginsDir,
@@ -763,6 +765,13 @@ export async function setPluginStateUnlocked(
   if (!loader.get(pluginId)) {
     throw new PluginManageError("Plugin not found", 404, "NOT_FOUND");
   }
+  if (enabled && !mayRunInSafeMode(pluginId, loader.list())) {
+    throw new PluginManageError(
+      "Safe mode is on, so only layout and theme plugins can start",
+      409,
+      "SAFE_MODE",
+    );
+  }
   const plan = await planStateChange(pluginId, enabled);
 
   if (enabled) {
@@ -959,7 +968,11 @@ export function installPlugin(
   return serialized(async () => {
     const { createCurrentPluginRepository } = await repos();
     const repository = createCurrentPluginRepository();
-    if (await repository.findById(pluginId)) {
+    // A record with no code is a plugin an older image shipped: install fills it in.
+    if (
+      (await repository.findById(pluginId)) &&
+      getPluginRuntime().loader.get(pluginId)
+    ) {
       throw new PluginManageError(
         "Plugin is already installed",
         409,
@@ -1018,6 +1031,63 @@ export function installPlugin(
   });
 }
 
+/**
+ * Called at boot before plugins start. A plugin the database has on but the
+ * image no longer ships (an update to a smaller image tag) is fetched from the
+ * official registry, so nothing an install used goes missing. One that cannot
+ * be fetched stays as it was and is tried again on the next start.
+ */
+export function restoreMissingPlugins(): Promise<LoadedPlugin[]> {
+  return serialized(async () => {
+    const { createCurrentPluginRepository } = await repos();
+    const repository = createCurrentPluginRepository();
+    const { loader } = getPluginRuntime();
+    const ids = missingShippedPluginIds(
+      await repository.listAll(),
+      new Set(loader.list().map((plugin) => plugin.id)),
+      await readUninstalled(),
+    );
+    const restored: LoadedPlugin[] = [];
+    for (const id of ids) {
+      try {
+        const record = await repository.findById(id);
+        const { source, release } = await requireRelease(
+          id,
+          record?.pinnedVersion ?? undefined,
+          channelOf(record),
+          OFFICIAL_REGISTRY_ID,
+        );
+        const plugin = await swapIn(id, { release, source });
+        await repository.update(id, {
+          registryId: source.id,
+          tier: tierFor(plugin, source),
+        });
+        await grantDeclared(plugin, null);
+        restored.push(plugin);
+        pluginLogger.info(
+          `Restored ${id}@${release.version} from the registry`,
+          {
+            operation: "plugin_restore_missing",
+          },
+        );
+      } catch (error) {
+        const message = error instanceof Error ? error.message : String(error);
+        pluginLogger.warn(`Could not restore ${id}: ${message}`, {
+          operation: "plugin_restore_missing",
+        });
+        // The registry is down or offline, so the rest would fail the same way.
+        if (
+          error instanceof PluginManageError &&
+          error.code === "REGISTRY_UNREACHABLE"
+        ) {
+          break;
+        }
+      }
+    }
+    return restored;
+  });
+}
+
 export function updatePlugin(
   pluginId: string,
   options: InstallOptions,

src/backend/plugins/registry-index.ts

@@ -12,6 +12,7 @@
 
 import crypto from "node:crypto";
 import fs from "node:fs";
+import { isIP } from "node:net";
 import path from "node:path";
 import semver from "semver";
 import {
@@ -23,7 +24,11 @@ import {
   youtubeVideoId,
 } from "@termix-ssh/plugin-sdk/manifest";
 import { getLocalVersion } from "../utils/app-version.js";
-import { safeOutboundFetch } from "../utils/safe-outbound-fetch.js";
+import {
+  isBlockedAddress,
+  safeOutboundFetch,
+} from "../utils/safe-outbound-fetch.js";
+import { fetchWithProxy, getProxyAgent } from "../utils/proxy-agent.js";
 import { pluginLogger } from "../utils/logger.js";
 import {
   COMMUNITY_PLUGIN_KEYS,
@@ -278,15 +283,72 @@ export function canRunRelease(
   );
 }
 
+/**
+ * Hosts the admin lets registry fetches reach on a private address, like a
+ * registry in the LAN. Matched by host name on any port, also when another
+ * index or a redirect points there; every other host stays blocked.
+ */
+export function getRegistryPrivateHosts(): string[] {
+  return (process.env.TERMIX_PLUGIN_REGISTRY_PRIVATE_HOSTS ?? "")
+    .split(",")
+    .map((value) => value.trim())
+    .filter(Boolean)
+    .map(normalizePrivateHost)
+    .filter((host): host is string => host !== undefined);
+}
+
+/**
+ * The host in the form safeOutboundFetch compares against, or undefined when
+ * the entry carries more than a host, like a scheme, port, path or user.
+ */
+function normalizePrivateHost(entry: string): string | undefined {
+  const candidate = isIP(entry) === 6 ? `[${entry}]` : entry;
+  if (/[/?#@\\]|:\d*$/.test(candidate)) return undefined;
+  try {
+    return new URL(`http://${candidate}`).hostname.replace(/^\[|\]$/g, "");
+  } catch {
+    return undefined;
+  }
+}
+
+/**
+ * With HTTP_PROXY or HTTPS_PROXY set, registry traffic goes through the proxy,
+ * which does its own name lookup. Only the URL itself is checked here: web
+ * pages only, no logins in it, and no private address typed in as a literal.
+ */
+function fetchThroughProxy(
+  url: string,
+  options: RequestInit,
+  privateHosts: readonly string[],
+): Promise<Response> {
+  const parsed = new URL(url);
+  const host = parsed.hostname.replace(/^\[|\]$/g, "");
+  if (
+    !["http:", "https:"].includes(parsed.protocol) ||
+    parsed.username ||
+    parsed.password
+  ) {
+    throw new Error("Invalid outbound URL");
+  }
+  if (isIP(host) && isBlockedAddress(host) && !privateHosts.includes(host)) {
+    throw new Error("Private destinations are not allowed");
+  }
+  return fetchWithProxy(url, options);
+}
+
 /** Follows redirects by hand so each hop still gets the outbound checks. */
 async function fetchFollowing(url: string): Promise<Response> {
+  const privateHosts = getRegistryPrivateHosts();
   let current = url;
   for (let hop = 0; hop <= MAX_REDIRECTS; hop++) {
-    const response = await safeOutboundFetch(current, {
+    const options: RequestInit = {
       method: "GET",
       redirect: "manual",
       headers: { "User-Agent": "Termix" },
-    });
+    };
+    const response = getProxyAgent(current)
+      ? await fetchThroughProxy(current, options, privateHosts)
+      : await safeOutboundFetch(current, options, privateHosts);
     if (response.status >= 300 && response.status < 400) {
       const location = response.headers.get("location");
       if (!location) throw new Error(`redirect without a location: ${current}`);

src/backend/plugins/safe-mode.ts

@@ -0,0 +1,42 @@
+import type { PluginManifest } from "./manifest.js";
+
+/** TERMIX_SAFE_MODE=1 starts only the plugins that draw the app. */
+export function safeModeOn(): boolean {
+  const value = process.env.TERMIX_SAFE_MODE?.trim().toLowerCase();
+  return value === "1" || value === "true";
+}
+
+function isLookPlugin(manifest: PluginManifest): boolean {
+  return (
+    (manifest.contributes?.layouts?.length ?? 0) > 0 ||
+    (manifest.contributes?.themes?.length ?? 0) > 0
+  );
+}
+
+/** Layout and theme plugins, plus the plugins they need to start. */
+export function safeModePluginIds(
+  plugins: { id: string; manifest: PluginManifest }[],
+): Set<string> {
+  const byId = new Map(plugins.map((plugin) => [plugin.id, plugin]));
+  const allowed = new Set<string>();
+  const add = (id: string) => {
+    const plugin = byId.get(id);
+    if (!plugin || allowed.has(id)) return;
+    allowed.add(id);
+    for (const dependency of Object.keys(plugin.manifest.dependencies ?? {})) {
+      add(dependency);
+    }
+  };
+  for (const plugin of plugins) {
+    if (isLookPlugin(plugin.manifest)) add(plugin.id);
+  }
+  return allowed;
+}
+
+/** Whether a plugin may run now. Always true outside safe mode. */
+export function mayRunInSafeMode(
+  pluginId: string,
+  plugins: { id: string; manifest: PluginManifest }[],
+): boolean {
+  return !safeModeOn() || safeModePluginIds(plugins).has(pluginId);
+}

src/backend/sync/shared-copy-guard.ts

@@ -7,6 +7,8 @@ import { createCurrentRepositoryContext } from "../database/repositories/factory
  * On a linked desktop, hosts and credentials someone shared with the account
  * are read-only copies kept in step by sync. Editing or deleting one here
  * would be undone by the next sync, so it is refused with a clear reason.
+ * A host's connection origin only means something on this device, so that one
+ * field can still be changed.
  */
 export function rejectSharedCopyWrites(
   kind: "host" | "credential",
@@ -25,6 +27,19 @@ export function rejectSharedCopyWrites(
         .where(eq(table.id, Number(match[1])))
         .limit(1);
       if (row?.sharedSource) {
+        const origin = req.body?.connectionOrigin;
+        if (
+          kind === "host" &&
+          req.method === "PUT" &&
+          (origin === "local" || origin === "remote")
+        ) {
+          await createCurrentRepositoryContext()
+            .drizzle.update(hosts)
+            .set({ connectionOrigin: origin })
+            .where(eq(hosts.id, Number(match[1])));
+          res.json({ id: Number(match[1]), connectionOrigin: origin });
+          return;
+        }
         res.status(403).json({
           error: "This was shared with you and is managed on the server",
           code: "SHARED_COPY",

src/backend/tests/database/routes/look.test.ts

@@ -102,6 +102,7 @@ beforeEach(async () => {
   state.defaultLookIds = [];
   state.installed = [];
   delete process.env.TERMIX_SAFE_LAYOUT;
+  delete process.env.TERMIX_SAFE_MODE;
 
   const app = express();
   app.use(express.json());
@@ -113,6 +114,7 @@ beforeEach(async () => {
 
 afterEach(async () => {
   delete process.env.TERMIX_SAFE_LAYOUT;
+  delete process.env.TERMIX_SAFE_MODE;
   await new Promise<void>((resolve) => server.close(() => resolve()));
 });
 
@@ -138,6 +140,7 @@ describe("GET /user-preferences/look", () => {
       defaults: { layout: null, theme: null },
       defaultLook: { layout: null, theme: null },
       safeLayout: false,
+      safeMode: false,
       unavailable: [],
     });
   });
@@ -159,6 +162,7 @@ describe("GET /user-preferences/look", () => {
       { id: "other", version: null, layouts: [], themes: [], error: "y" },
     ];
     process.env.TERMIX_SAFE_LAYOUT = "1";
+    process.env.TERMIX_SAFE_MODE = "1";
 
     const { body } = await getLook();
     expect(body).toMatchObject({
@@ -167,6 +171,7 @@ describe("GET /user-preferences/look", () => {
       defaults: { layout: "admin-layout", theme: "gruvbox" },
       defaultLook: { layout: "shipped", theme: "ink" },
       safeLayout: true,
+      safeMode: true,
     });
     expect(body.unavailable.map((plugin: { id: string }) => plugin.id)).toEqual(
       ["broken"],

src/backend/tests/database/routes/plugins.test.ts

@@ -488,6 +488,26 @@ describe("plugins route", () => {
     }
   });
 
+  it("reports an enabled plugin that safe mode keeps off", async () => {
+    state.plugins.set("sample-plugin", makePlugin({ state: "enabled" }));
+
+    const read = async () =>
+      (
+        (await (await fetch(`${baseUrl}/plugins`)).json()) as Array<{
+          state: string;
+          enabled: boolean;
+        }>
+      )[0];
+
+    expect((await read()).state).not.toBe("safe-mode");
+    process.env.TERMIX_SAFE_MODE = "1";
+    try {
+      expect(await read()).toMatchObject({ state: "safe-mode", enabled: true });
+    } finally {
+      delete process.env.TERMIX_SAFE_MODE;
+    }
+  });
+
   it("grants a declared capability", async () => {
     state.plugins.set("sample-plugin", makePlugin());
 

src/backend/tests/plugins/boot-state.test.ts

@@ -1,5 +1,8 @@
 import { describe, expect, it } from "vitest";
-import { startablePluginIds } from "../../plugins/boot-state.js";
+import {
+  missingShippedPluginIds,
+  startablePluginIds,
+} from "../../plugins/boot-state.js";
 
 describe("startablePluginIds", () => {
   it("starts enabled plugins and retries ones that failed or were blocked", () => {
@@ -13,3 +16,25 @@ describe("startablePluginIds", () => {
     expect([...ids].sort()).toEqual(["a", "b", "c"]);
   });
 });
+
+describe("missingShippedPluginIds", () => {
+  const records = [
+    { id: "gone", tier: "bundled", state: "enabled" },
+    { id: "here", tier: "bundled", state: "enabled" },
+    { id: "off", tier: "bundled", state: "disabled" },
+    { id: "failed", tier: "bundled", state: "failed" },
+    { id: "community", tier: "community", state: "enabled" },
+    { id: "removed", tier: "bundled", state: "enabled" },
+  ];
+
+  it("lists shipped plugins that are on but not in the image", () => {
+    expect(
+      missingShippedPluginIds(records, new Set(["here"]), new Set(["removed"])),
+    ).toEqual(["failed", "gone"]);
+  });
+
+  it("finds nothing when every plugin is present", () => {
+    const present = new Set(records.map((record) => record.id));
+    expect(missingShippedPluginIds(records, present, new Set())).toEqual([]);
+  });
+});

src/backend/tests/plugins/manage.test.ts

@@ -621,6 +621,26 @@ describe("dependencies", () => {
   });
 });
 
+describe("safe mode", () => {
+  afterEach(() => {
+    delete process.env.TERMIX_SAFE_MODE;
+  });
+
+  it("refuses to start a plugin that is not a layout or theme, but still stops one", async () => {
+    createFixturePlugin({ id: "base", root: bundled });
+    const loader = await boot();
+    await manage.setPluginState("base", false);
+
+    process.env.TERMIX_SAFE_MODE = "1";
+    await expect(manage.setPluginState("base", true)).rejects.toMatchObject({
+      status: 409,
+      code: "SAFE_MODE",
+    });
+    expect(loader.get("base")?.state).toBe("stopped");
+    expect(db.rows.get("base")?.state).toBe("disabled");
+  });
+});
+
 describe("reloading a bundled plugin for the dev runner", () => {
   it("loads the rebuilt copy and restarts what depends on it", async () => {
     createFixturePlugin({ id: "base", root: bundled });

src/backend/tests/plugins/registry-index.test.ts

@@ -8,10 +8,23 @@ import * as tar from "tar";
 const fetchMock = vi.hoisted(() => vi.fn());
 const testKey = vi.hoisted(() => ({ value: null as null | object }));
 
-vi.mock("../../utils/safe-outbound-fetch.js", () => ({
+vi.mock("../../utils/safe-outbound-fetch.js", async (importOriginal) => ({
+  ...(await importOriginal<
+    typeof import("../../utils/safe-outbound-fetch.js")
+  >()),
   safeOutboundFetch: fetchMock,
 }));
 
+const proxyMock = vi.hoisted(() => ({
+  on: false,
+  fetch: vi.fn(),
+}));
+
+vi.mock("../../utils/proxy-agent.js", () => ({
+  getProxyAgent: () => (proxyMock.on ? {} : undefined),
+  fetchWithProxy: proxyMock.fetch,
+}));
+
 vi.mock("../../utils/app-version.js", () => ({
   getLocalVersion: () => "26.10.3",
 }));
@@ -43,9 +56,11 @@ vi.mock("../../plugins/trust.js", async (importOriginal) => {
 import {
   communitySource,
   downloadRelease,
+  fetchIndexAt,
   fetchRegistryIndex,
   fetchRegistryStats,
   findRelease,
+  getRegistryPrivateHosts,
   latestOnChannel,
   getStatsUrl,
   canRunRelease,
@@ -409,6 +424,91 @@ describe("fetchRegistryIndex", () => {
   });
 });
 
+describe("registry fetches with a proxy", () => {
+  afterEach(() => {
+    proxyMock.on = false;
+    proxyMock.fetch.mockReset();
+  });
+
+  it("goes through the proxy when one is configured", async () => {
+    proxyMock.on = true;
+    proxyMock.fetch.mockResolvedValueOnce(
+      response(JSON.stringify({ plugins: [] })),
+    );
+    await fetchIndexAt("https://registry.example/index.json");
+    expect(proxyMock.fetch).toHaveBeenCalledTimes(1);
+    expect(fetchMock).not.toHaveBeenCalled();
+  });
+
+  it("still refuses a private address typed in as a literal", async () => {
+    proxyMock.on = true;
+    await expect(fetchIndexAt("https://127.0.0.1/index.json")).rejects.toThrow(
+      "Private destinations are not allowed",
+    );
+    expect(proxyMock.fetch).not.toHaveBeenCalled();
+  });
+});
+
+describe("private registry hosts", () => {
+  afterEach(() => {
+    delete process.env.TERMIX_PLUGIN_REGISTRY_PRIVATE_HOSTS;
+  });
+
+  it("reads a comma separated list of host names", () => {
+    process.env.TERMIX_PLUGIN_REGISTRY_PRIVATE_HOSTS =
+      " GitLab.lan ,, 192.168.1.5 ";
+    expect(getRegistryPrivateHosts()).toEqual(["gitlab.lan", "192.168.1.5"]);
+    delete process.env.TERMIX_PLUGIN_REGISTRY_PRIVATE_HOSTS;
+    expect(getRegistryPrivateHosts()).toEqual([]);
+  });
+
+  it("brings each entry into the form the fetch compares against", () => {
+    process.env.TERMIX_PLUGIN_REGISTRY_PRIVATE_HOSTS =
+      "GitLab.LAN,[FD00::0001],fd00::2,bücher.lan";
+    expect(getRegistryPrivateHosts()).toEqual([
+      "gitlab.lan",
+      "fd00::1",
+      "fd00::2",
+      "xn--bcher-kva.lan",
+    ]);
+  });
+
+  it("drops entries with more than a host", () => {
+    process.env.TERMIX_PLUGIN_REGISTRY_PRIVATE_HOSTS =
+      "gitlab.lan:8443,https://git.lan,[fd00::1]:80,nas.lan";
+    expect(getRegistryPrivateHosts()).toEqual(["nas.lan"]);
+  });
+
+  it("allows the listed hosts on every hop", async () => {
+    process.env.TERMIX_PLUGIN_REGISTRY_PRIVATE_HOSTS = "gitlab.lan";
+    fetchMock
+      .mockResolvedValueOnce(
+        response("", 302, { location: "https://gitlab.lan/raw/index.json" }),
+      )
+      .mockResolvedValueOnce(response(JSON.stringify({ plugins: [] })));
+    await fetchIndexAt("https://gitlab.lan/index.json");
+    expect(fetchMock.mock.calls.map((call) => call[2])).toEqual([
+      ["gitlab.lan"],
+      ["gitlab.lan"],
+    ]);
+  });
+
+  it("still blocks a redirect to a private host that is not listed", async () => {
+    process.env.TERMIX_PLUGIN_REGISTRY_PRIVATE_HOSTS = "gitlab.lan";
+    const actual = await vi.importActual<
+      typeof import("../../utils/safe-outbound-fetch.js")
+    >("../../utils/safe-outbound-fetch.js");
+    fetchMock
+      .mockResolvedValueOnce(
+        response("", 302, { location: "https://127.0.0.1/index.json" }),
+      )
+      .mockImplementationOnce(actual.safeOutboundFetch);
+    await expect(fetchIndexAt("https://gitlab.lan/index.json")).rejects.toThrow(
+      "Private destinations are not allowed",
+    );
+  });
+});
+
 /** A real .tmxplug holding only a manifest, enough for the checks. */
 function pack(manifest: Record<string, unknown>): Buffer {
   const dir = fs.mkdtempSync(path.join(os.tmpdir(), "termix-pack-"));

src/backend/tests/plugins/safe-mode.test.ts

@@ -0,0 +1,62 @@
+import { afterEach, describe, expect, it } from "vitest";
+import {
+  mayRunInSafeMode,
+  safeModeOn,
+  safeModePluginIds,
+} from "../../plugins/safe-mode.js";
+import type { PluginManifest } from "../../plugins/manifest.js";
+
+function plugin(id: string, manifest: Partial<PluginManifest> = {}) {
+  return { id, manifest: { id, ...manifest } as PluginManifest };
+}
+
+const plugins = [
+  plugin("layout", {
+    contributes: { layouts: [{ id: "classic" }] },
+    dependencies: { helper: "^1.0.0" },
+  } as Partial<PluginManifest>),
+  plugin("themes", {
+    contributes: { themes: [{ id: "dark" }] },
+  } as Partial<PluginManifest>),
+  plugin("helper"),
+  plugin("docker"),
+];
+
+afterEach(() => {
+  delete process.env.TERMIX_SAFE_MODE;
+});
+
+describe("safeModeOn", () => {
+  it("reads 1 and true, anything else is off", () => {
+    expect(safeModeOn()).toBe(false);
+    process.env.TERMIX_SAFE_MODE = "1";
+    expect(safeModeOn()).toBe(true);
+    process.env.TERMIX_SAFE_MODE = " TRUE ";
+    expect(safeModeOn()).toBe(true);
+    process.env.TERMIX_SAFE_MODE = "0";
+    expect(safeModeOn()).toBe(false);
+  });
+});
+
+describe("safeModePluginIds", () => {
+  it("keeps layout and theme plugins and what they depend on", () => {
+    expect([...safeModePluginIds(plugins)].sort()).toEqual([
+      "helper",
+      "layout",
+      "themes",
+    ]);
+  });
+});
+
+describe("mayRunInSafeMode", () => {
+  it("lets every plugin run when safe mode is off", () => {
+    expect(mayRunInSafeMode("docker", plugins)).toBe(true);
+  });
+
+  it("only lets look plugins run when safe mode is on", () => {
+    process.env.TERMIX_SAFE_MODE = "1";
+    expect(mayRunInSafeMode("docker", plugins)).toBe(false);
+    expect(mayRunInSafeMode("layout", plugins)).toBe(true);
+    expect(mayRunInSafeMode("helper", plugins)).toBe(true);
+  });
+});

src/backend/tests/sync/shared-copy-guard.test.ts

@@ -0,0 +1,77 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const h = vi.hoisted(() => ({
+  row: { sharedSource: '{"owner":"x"}' } as { sharedSource: string | null },
+  updates: [] as unknown[],
+}));
+
+vi.mock("../../database/repositories/factory.js", () => ({
+  createCurrentRepositoryContext: () => ({
+    drizzle: {
+      select: () => ({
+        from: () => ({ where: () => ({ limit: async () => [h.row] }) }),
+      }),
+      update: () => ({
+        set: (values: unknown) => ({
+          where: async () => {
+            h.updates.push(values);
+          },
+        }),
+      }),
+    },
+  }),
+}));
+
+const { rejectSharedCopyWrites } =
+  await import("../../sync/shared-copy-guard.js");
+
+function run(body: Record<string, unknown>) {
+  const guard = rejectSharedCopyWrites("host", /^\/db\/host\/(\d+)$/);
+  const res = {
+    code: 0,
+    payload: undefined as unknown,
+    status(code: number) {
+      this.code = code;
+      return this;
+    },
+    json(payload: unknown) {
+      this.payload = payload;
+      return this;
+    },
+  };
+  const next = vi.fn();
+  return guard(
+    { method: "PUT", path: "/db/host/5", body } as never,
+    res as never,
+    next,
+  ).then(() => ({ res, next }));
+}
+
+beforeEach(() => {
+  process.env.ELECTRON_EMBEDDED = "true";
+  h.row = { sharedSource: '{"owner":"x"}' };
+  h.updates = [];
+});
+
+describe("shared copy guard", () => {
+  it("refuses edits to a shared copy", async () => {
+    const { res, next } = await run({ name: "new" });
+    expect(res.code).toBe(403);
+    expect(next).not.toHaveBeenCalled();
+    expect(h.updates).toEqual([]);
+  });
+
+  it("still lets the connection origin change on this device", async () => {
+    const { res, next } = await run({ name: "new", connectionOrigin: "local" });
+    expect(res.code).toBe(0);
+    expect(res.payload).toMatchObject({ connectionOrigin: "local" });
+    expect(next).not.toHaveBeenCalled();
+    expect(h.updates).toEqual([{ connectionOrigin: "local" }]);
+  });
+
+  it("passes hosts that are not shared copies", async () => {
+    h.row = { sharedSource: null };
+    const { next } = await run({ name: "new" });
+    expect(next).toHaveBeenCalled();
+  });
+});