docs: finalise Arma 3 UX enhancement plan and update project docs

- .claude/plan/arma3-ux-enhancement.md: full plan review pass
  - Add Progress Tracker table for session handoff
  - Fix Phase 1 field names to match ServerConfig model (password_admin,
    battleye, disable_von)
  - Fix Phase 2 rotation endpoints to use ServerService(db) inline pattern
  - Fix Phase 4 router/service: add get_by_slot() to PlayerRepository,
    add get_rcon_client() to ThreadRegistry, fix BanRepository.create()
    signature (expires_at not duration_minutes), correct router pattern
  - Fix Phase 6: already implemented, mark as SKIP
  - Fix CSS class names: btn-secondary→btn-ghost, input-base→neu-input
  - Add 19 implementation decisions from Q&A session to Coding Conventions
- CLAUDE.md: update status table, type mapping table, add plan summary
  and new endpoint list, add key implementation gotchas section
- frontend/README.md: replace Vite boilerplate with project README
- frontend/tests-e2e: E2E test improvements from previous session
  (mock-based login error test, full dashboard mock coverage)

frontend/tests-e2e/auth/login.spec.ts

@@ -29,11 +29,18 @@ test.describe("Login Flow", () => {
   });
 
   test("should show error on invalid credentials", async ({ page }) => {
+    // Mock the backend to return 401 for invalid login
+    await page.route("**/api/auth/login", (route) =>
+      route.fulfill({
+        status: 401,
+        contentType: "application/json",
+        body: JSON.stringify({
+          detail: "Invalid credentials",
+        }),
+      }),
+    );
+
     await loginPage.login("invalid", "credentials");
-    await page.waitForResponse(
-      (resp) => resp.url().includes("/api/auth/login"),
-      { timeout: 10_000 },
-    ).catch(() => {});
     await expect(loginPage.errorMessage).toBeVisible({ timeout: 10_000 });
   });
 
@@ -52,7 +59,16 @@ test.describe("Login Flow", () => {
       }),
     );
 
-    await page.route("**/api/servers*", (route) =>
+    // Mock auth/me and servers so the dashboard loads
+    await page.route("**/api/auth/me", (route) =>
+      route.fulfill({
+        status: 200,
+        contentType: "application/json",
+        body: JSON.stringify({ success: true, data: { id: 1, username: "admin", role: "admin" }, error: null }),
+      }),
+    );
+
+    await page.route("**/api/servers**", (route) =>
       route.fulfill({
         status: 200,
         contentType: "application/json",
@@ -66,8 +82,14 @@ test.describe("Login Flow", () => {
   });
 
   test("should show loading state while submitting", async ({ page }) => {
-    await page.route("**/api/auth/login", (route) =>
-      route.fulfill({
+    let resolveLogin: (value: unknown) => void;
+    const loginPromise = new Promise((resolve) => {
+      resolveLogin = resolve;
+    });
+
+    await page.route("**/api/auth/login", async (route) => {
+      await loginPromise;
+      await route.fulfill({
         status: 200,
         contentType: "application/json",
         body: JSON.stringify({
@@ -77,19 +99,19 @@ test.describe("Login Flow", () => {
             user: { id: 1, username: "admin", role: "admin" },
           },
         }),
-        delay: 500,
-      }),
-    );
+      });
+    });
 
-    await page.route("**/api/servers*", (route) =>
-      route.fulfill({
-        status: 200,
-        contentType: "application/json",
-        body: JSON.stringify({ success: true, data: [] }),
-      }),
-    );
+    await loginPage.usernameInput.fill("admin");
+    await loginPage.passwordInput.fill("password");
 
-    await loginPage.login("admin", "password");
-    await expect(loginPage.submitButton).toContainText("Signing in...");
+    // Click submit and immediately check for loading state
+    await loginPage.submitButton.click();
+
+    // The button should show "Signing in..." while the request is pending
+    await expect(loginPage.submitButton).toContainText("Signing in...", { timeout: 5_000 });
+
+    // Resolve the login to let the test finish
+    resolveLogin!("done");
   });
 });