refactor(e2e): split spec files under 300-line limit

- phase-c.test.ts (626 lines) → phase-c-ui.test.ts (279), phase-c-tabs.test.ts
  (272), phase-c-llm.test.ts (76) — all 11 scenarios preserved
- agor.test.ts (799 lines) → smoke.test.ts (47), workspace.test.ts (79),
  settings.test.ts (247), features.test.ts (488) — split in progress
- Reset-to-home-state hooks added to stateful before() blocks
- wdio.conf.js specs array updated for all new filenames

tests/e2e/specs/smoke.test.ts

@@ -0,0 +1,47 @@
+import { browser, expect } from '@wdio/globals';
+
+describe('BTerminal — Smoke Tests', () => {
+  it('should render the application window', async () => {
+    // Wait for the app to fully load before any tests
+    await browser.waitUntil(
+      async () => (await browser.getTitle()) === 'BTerminal',
+      { timeout: 10_000, timeoutMsg: 'App did not load within 10s' },
+    );
+    const title = await browser.getTitle();
+    expect(title).toBe('BTerminal');
+  });
+
+  it('should display the status bar', async () => {
+    const statusBar = await browser.$('.status-bar');
+    await expect(statusBar).toBeDisplayed();
+  });
+
+  it('should show version text in status bar', async () => {
+    const version = await browser.$('.status-bar .version');
+    await expect(version).toBeDisplayed();
+    const text = await version.getText();
+    expect(text).toContain('BTerminal');
+  });
+
+  it('should display the sidebar rail', async () => {
+    const sidebarRail = await browser.$('.sidebar-rail');
+    await expect(sidebarRail).toBeDisplayed();
+  });
+
+  it('should display the workspace area', async () => {
+    const workspace = await browser.$('.workspace');
+    await expect(workspace).toBeDisplayed();
+  });
+
+  it('should toggle sidebar with settings button', async () => {
+    const settingsBtn = await browser.$('.rail-btn');
+    await settingsBtn.click();
+
+    const sidebarPanel = await browser.$('.sidebar-panel');
+    await expect(sidebarPanel).toBeDisplayed();
+
+    // Click again to close
+    await settingsBtn.click();
+    await expect(sidebarPanel).not.toBeDisplayed();
+  });
+});