Add release runtime bootstrap implementation with unit and E2E tests

- Create `releaseBootstrap.js` service to handle runtime configuration and remote frontend loading.
- Integrate runtime-aware API URL resolution across components and services.
- Update i18n phrases to clarify new domains for `ssl_domain_message`.
- Enhance unit and E2E tests to validate runtime-based frontend loading and fallback behavior.
- Refactor session-related API calls and incorporate runtime-configured base URLs.

tests/e2e/release-channel-unavailable.spec.js

@@ -46,6 +46,75 @@ const availableRuntime = () => ({
   },
 });
 
+const runtimeWithSelectableReleaseDetails = () => ({
+  ...unavailableRuntime,
+  versions: {
+    frontend: null,
+    api: null,
+    bundle_id: null,
+  },
+  availability: {
+    configured: false,
+    missing: ["release_bundle"],
+    status: "unconfigured",
+  },
+  available_channels: [
+    {
+      channel: {
+        id: 1,
+        slug: "stable",
+        name: "Stable",
+        description: "Standard production channel.",
+        enabled: true,
+        default_channel: true,
+      },
+      versions: {
+        frontend: {
+          version_label: "frontend-stable",
+          commit_sha: "abc1234567890000111122223333444455556666",
+          deployed_at: "2026-05-18T07:45:00.000Z",
+        },
+        api: {
+          version_label: "api-stable",
+          commit_sha: "def456789abc0000111122223333444455556666",
+          deployed_at: "2026-05-18T07:47:00.000Z",
+        },
+        bundle_id: 31,
+        bundle: {
+          id: 31,
+          promoted_at: "2026-05-18T08:00:00.000Z",
+        },
+      },
+      availability: {
+        configured: true,
+        missing: [],
+        status: "ready",
+      },
+    },
+    {
+      channel: unavailableRuntime.channel,
+      versions: {
+        frontend: {
+          version_label: "frontend-canary",
+          commit_sha: "c0ffee0000001111222233334444555566667777",
+          deployed_at: "2026-05-19T08:15:00.000Z",
+        },
+        api: {
+          version_label: "api-canary",
+          commit_sha: "feedface00001111222233334444555566667777",
+          deployed_at: "2026-05-19T08:18:00.000Z",
+        },
+        bundle_id: null,
+      },
+      availability: {
+        configured: false,
+        missing: ["release_bundle"],
+        status: "unconfigured",
+      },
+    },
+  ],
+});
+
 async function boot(page, runtime = unavailableRuntime, locale = "en") {
   await page.addInitScript((selectedLocale) => {
     window.localStorage.setItem("locale", selectedLocale);
@@ -85,6 +154,33 @@ test("users assigned to an unconfigured release channel can ignore the guard tem
   await page.evaluate(() => window.localStorage.removeItem("release_channel_unavailable_ignore_until"));
 });
 
+test("release channel choices show git commit and release time when available", async ({ page }) => {
+  const runtime = runtimeWithSelectableReleaseDetails();
+  await boot(page, runtime);
+  await page.route("**/release/runtime", async (route) => {
+    await route.fulfill(json({ data: runtime }));
+  });
+
+  await page.goto("/user", { waitUntil: "domcontentloaded" });
+  const guard = page.getByTestId("release-channel-unavailable-page");
+  await expect(guard).toBeVisible();
+
+  const canary = page.getByTestId("release-channel-option-canary");
+  await expect(canary).toBeVisible();
+  await expect(canary).toContainText("Release bundle");
+  await expect(page.getByTestId("release-channel-option-canary-frontend-release")).toContainText("c0ffee000000");
+  await expect(page.getByTestId("release-channel-option-canary-frontend-release")).toContainText(
+    /May 19, 2026|19 May 2026/
+  );
+  await expect(page.getByTestId("release-channel-option-canary-api-release")).toContainText("feedface0000");
+  await expect(page.getByTestId("release-channel-option-canary-api-release")).toContainText(/May 19, 2026|19 May 2026/);
+
+  await expect(page.getByTestId("release-channel-option-stable-bundle-release")).toContainText("#31");
+  await expect(page.getByTestId("release-channel-option-stable-bundle-release")).toContainText(
+    /May 18, 2026|18 May 2026/
+  );
+});
+
 test("predefined release channel text is localized on the guard page", async ({ page }) => {
   const internalRuntime = {
     ...unavailableRuntime,