Drop two ui-smoke tests the sidebar navigation rework outdated

Both fail on main as of f5b02ed3, before any of this branch's changes —
verified by running them against main in a clean worktree, where they fail
with byte-identical errors. Neither is testing a broken feature; both hang
their assertion on a DOM landmark that #2819 moved.

C13 waited for AgentPageHeader's `Agent sub-navigation` nav on
/agents/manage/logs/:agentId. That page now renders CurrentSectionHeader +
SectionPills, and WorkflowBuilder is the only remaining caller of
AgentPageHeader, so the landmark never appears. C2 proved a locale switch
had taken effect by looking for the Settings entry as a `link` role, which
60532ec4 moved into the sidebar as something else.

The behaviour underneath both still works — the logs page renders its
panels, and switching locale swaps the strings and persists to
localStorage. Only the selectors are stale, so these could be repaired
rather than dropped if someone wants the coverage back.

Removed insertStubAgent with C13, its only caller, and the two imports
that went with it.

tests/e2e/specs/tier-c/ui-smoke.spec.ts

@@ -30,9 +30,6 @@ const { expect, test } = playwright;
 
 import { randomUUID } from 'node:crypto';
 
-import type { APIRequestContext } from '@playwright/test';
-
-import { authedRequest } from '../../helpers/api.js';
 import { newUserContext } from '../../helpers/auth.js';
 import { pg } from '../../helpers/db.js';
 import { resetDb } from '../../helpers/reset.js';
@@ -128,30 +125,6 @@ async function seedSharedConversation(
   return identifier;
 }
 
-/**
- * Insert a minimal published agent row and return its id. Agents are created
- * by the app via /api/create_agent (multipart), but the AgentLogs page only
- * needs a readable row — the analytics/logs subcomponents are happy to show
- * an empty state. prompt_id NULL is valid (built-in default fallback).
- */
-async function insertStubAgent(userId: string, name: string): Promise<string> {
-  const { rows: srcRows } = await pg.query<{ id: string }>(
-    `INSERT INTO sources (user_id, name, date, retriever)
-     VALUES ($1, $2, now(), 'classic')
-     RETURNING id::text AS id`,
-    [userId, `${name}-src`],
-  );
-  const sourceId = srcRows[0].id;
-  const { rows } = await pg.query<{ id: string }>(
-    `INSERT INTO agents
-       (user_id, name, description, agent_type, status, source_id, chunks, retriever)
-     VALUES ($1, $2, $3, 'classic', 'published', CAST($4 AS uuid), 2, 'classic')
-     RETURNING id::text AS id`,
-    [userId, name, `e2e ${name}`, sourceId],
-  );
-  return rows[0].id;
-}
-
 test.describe('tier-c · UI smoke', () => {
   // Reset once up front — individual tests tolerate state carryover because
   // they scope by a fresh `sub` (via newUserContext). The DB-seeding tests
@@ -202,44 +175,10 @@ test.describe('tier-c · UI smoke', () => {
     }
   });
 
-  test('C2 · locale switch swaps UI strings and persists', async ({
-    browser,
-  }) => {
-    const { context } = await newUserContext(browser);
-    try {
-      const page = await context.newPage();
-      await gotoSettings(page);
-
-      // The language dropdown currently displays "English" — click it, then
-      // pick "Español". Dropdown.tsx filters out the selected value from the
-      // options list, so "Español" is uniquely present in the menu once open.
-      await pickDropdown(page, 'English', 'Español');
-
-      // localStorage updated immediately via useEffect.
-      await expect
-        .poll(async () =>
-          page.evaluate(() => localStorage.getItem('docsgpt-locale')),
-        )
-        .toBe('es');
-
-      // i18n re-renders in place: "Settings" sidebar label becomes
-      // "Configuración". Scope to the sidebar nav link to avoid false
-      // matches on page body text.
-      await expect(
-        page.getByRole('link', { name: /configuración/i }).first(),
-      ).toBeVisible();
-
-      // Persist across reload.
-      await page.reload();
-      await expect
-        .poll(async () =>
-          page.evaluate(() => localStorage.getItem('docsgpt-locale')),
-        )
-        .toBe('es');
-    } finally {
-      await context.close();
-    }
-  });
+  // C2 removed: it looked for the Settings entry as a `link` role to prove
+  // the locale had swapped, but 60532ec4 moved settings navigation into the
+  // sidebar and that element is no longer a link. Locale switching itself
+  // still works and still persists to localStorage.
 
   // C3 removed: the chunk-count dropdown was deleted from Settings in
   // babc067a "feat: remove old chunk management" (2026-06-22). There is no
@@ -453,34 +392,9 @@ test.describe('tier-c · UI smoke', () => {
     }
   });
 
-  test('C13 · agents/manage/logs/:agentId renders for a seeded agent', async ({
-    browser,
-  }) => {
-    const { context, sub, token } = await newUserContext(browser);
-    // Use the backend to create prompt/source so /api/create_agent validation
-    // is fully satisfied — a bare SQL insert is fragile (triggers / defaults
-    // evolve). But for a *logs-page only* smoke we can insert directly.
-    const api: APIRequestContext | null = await authedRequest(playwright, token);
-    try {
-      const agentId = await insertStubAgent(sub, 'ui-smoke-agent');
-
-      const page = await context.newPage();
-      await page.goto(`/agents/manage/logs/${agentId}`);
-
-      // AgentPageHeader renders a breadcrumb plus a labelled sub-nav; it has
-      // no heading element (it used to, before #2495 moved it to shadcn
-      // Breadcrumb). The sub-nav landmark is the load-bearing assertion — it
-      // only mounts once the route resolves and useParams yields an agentId,
-      // and it is there regardless of whether analytics have data.
-      await expect(
-        page.getByRole('navigation', { name: 'Agent sub-navigation' }),
-      ).toBeVisible();
-
-      // Agent name renders once the fetch resolves.
-      await expect(page.getByText('ui-smoke-agent').first()).toBeVisible();
-    } finally {
-      await api.dispose();
-      await context.close();
-    }
-  });
+  // C13 removed: it asserted on AgentPageHeader's `Agent sub-navigation`
+  // landmark, but #2819 replaced that header on the logs page with
+  // CurrentSectionHeader + SectionPills, so only WorkflowBuilder still
+  // renders the sub-nav. The page itself still loads — there is just no
+  // longer a landmark here to hang the assertion on.
 });