Replace hand-rolled auth with Laravel Breeze (Livewire stack)

Adds the auth Breeze scaffolds that were missing before: password
reset and email verification, plus a profile page (update name/email,
change password, delete account). User now implements MustVerifyEmail
so verification is actually enforced, not just scaffolded.

This does mean accepting Tailwind v3 (postcss/tailwind.config.js)
over the v4 CSS-first setup the app started with, and Livewire drops
from ^4.3 to ^3.6.4 — both forced by Breeze/Volt's current
compatibility requirements. Restored the Instrument Sans font Breeze's
installer dropped so styling stays close to what we had.

Reconciliation, since Breeze's installer assumes a blank-slate app:
- Deleted the hand-rolled Login/Register Livewire components/views/
  test — superseded by Breeze's Volt-based auth pages
  (resources/views/livewire/pages/auth/*), which also cover
  forgot-password, reset-password, verify-email, and confirm-password.
- Deleted Breeze's own default welcome/dashboard views and its
  separate app layout + nav component — kept our existing
  components/layouts/app.blade.php as the one real app layout, used
  Breeze's minimal layouts/guest.blade.php only for the auth pages.
- Rewrote routes/web.php merging our routes (home, sites, discover)
  with routes/auth.php; replaced every hardcoded route('dashboard')
  reference (5 Blade files plus, easy to miss, a plain PHP controller
  VerifyEmailController) with sites.index.
- Logout: Breeze's Actions\Logout::__invoke() returns void, so wired
  directly as a route it silently no-ops instead of redirecting;
  fixed with a thin closure that calls it then redirects.
- Fixed Breeze's own generated tests (Auth/AuthenticationTest,
  RegistrationTest, EmailVerificationTest, PasswordConfirmationTest)
  where they assumed the deleted dashboard route/nav component.

Verified: full suite (28 tests, including Breeze's Registration/
Authentication/PasswordReset/PasswordConfirmation/PasswordUpdate/
EmailVerification/Profile tests plus our own GuestPreviewTest) passes
against the huginn_testing MySQL database. Also smoke-tested for real:
all key pages return 200, /profile redirects guests to /login, guest
preview capping still works, and a real password-reset email was
generated and logged with correct branding and a working link.

app/Livewire/Forms/LoginForm.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace App\Livewire\Forms;
+
+use Illuminate\Auth\Events\Lockout;
+use Illuminate\Support\Facades\Auth;
+use Illuminate\Support\Facades\RateLimiter;
+use Illuminate\Support\Str;
+use Illuminate\Validation\ValidationException;
+use Livewire\Attributes\Validate;
+use Livewire\Form;
+
+class LoginForm extends Form
+{
+    #[Validate('required|string|email')]
+    public string $email = '';
+
+    #[Validate('required|string')]
+    public string $password = '';
+
+    #[Validate('boolean')]
+    public bool $remember = false;
+
+    /**
+     * Attempt to authenticate the request's credentials.
+     *
+     * @throws ValidationException
+     */
+    public function authenticate(): void
+    {
+        $this->ensureIsNotRateLimited();
+
+        if (! Auth::attempt($this->only(['email', 'password']), $this->remember)) {
+            RateLimiter::hit($this->throttleKey());
+
+            throw ValidationException::withMessages([
+                'form.email' => trans('auth.failed'),
+            ]);
+        }
+
+        RateLimiter::clear($this->throttleKey());
+    }
+
+    /**
+     * Ensure the authentication request is not rate limited.
+     */
+    protected function ensureIsNotRateLimited(): void
+    {
+        if (! RateLimiter::tooManyAttempts($this->throttleKey(), 5)) {
+            return;
+        }
+
+        event(new Lockout(request()));
+
+        $seconds = RateLimiter::availableIn($this->throttleKey());
+
+        throw ValidationException::withMessages([
+            'form.email' => trans('auth.throttle', [
+                'seconds' => $seconds,
+                'minutes' => ceil($seconds / 60),
+            ]),
+        ]);
+    }
+
+    /**
+     * Get the authentication rate limiting throttle key.
+     */
+    protected function throttleKey(): string
+    {
+        return Str::transliterate(Str::lower($this->email).'|'.request()->ip());
+    }
+}