Add M3 error pages and the Markdown mail theme

Error pages for 401 to 503 in an error-view root appended to view.paths,
with an inline fallback when the Vite build is missing, and a mail theme
rendered from the application's scheme JSON, with opt-in header and
message components. Completes Phase 9.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V9NnLxnPp8vaaurb3Z1MFy

src/LivewireMaterialServiceProvider.php

@@ -14,6 +14,8 @@ class LivewireMaterialServiceProvider extends ServiceProvider
         $this->mergeConfigFrom(__DIR__.'/../config/livewire-material.php', 'livewire-material');
 
         $this->disableBladeIconsComponent();
+        $this->registerErrorViews();
+        $this->registerMailComponents();
     }
 
     public function boot(): void
@@ -33,6 +35,71 @@ class LivewireMaterialServiceProvider extends ServiceProvider
             $this->publishes([
                 __DIR__.'/../config/livewire-material.php' => config_path('livewire-material.php'),
             ], 'livewire-material-config');
+
+            $this->publishes([
+                static::errorViewPath().'/errors' => resource_path('views/errors'),
+            ], 'livewire-material-errors');
+
+            $this->publishes([
+                static::mailComponentPath().'/html' => resource_path('views/vendor/mail/html'),
+                static::mailComponentPath().'/text' => resource_path('views/vendor/mail/text'),
+            ], 'livewire-material-mail');
+        }
+    }
+
+    /**
+     * The error-view root: a folder holding only `errors/`.
+     */
+    public static function errorViewPath(): string
+    {
+        return dirname(__DIR__).'/resources/views/error-pages';
+    }
+
+    /**
+     * The mail component root, laid out like the framework's: `html/` and `text/`.
+     */
+    public static function mailComponentPath(): string
+    {
+        return dirname(__DIR__).'/resources/views/mail';
+    }
+
+    /**
+     * Append the error-view root to `view.paths`, after the application's own.
+     *
+     * The exception handler replaces the `errors` namespace each time it renders an HTTP
+     * exception, with every entry of `view.paths` plus `/errors` and the framework's views last
+     * (RegisterErrorViewPaths), so a namespace added with addNamespace() is gone by then; only a
+     * view path survives. That config is read at render time, but also once when the view
+     * finder is built: appended here, in register(), before any boot() resolves the view
+     * factory, the finder and `view:cache` see the same paths the handler does. Appending keeps
+     * `view.paths[0]` — Laravel's viewPath() — the application's, and puts the application's
+     * own `resources/views/errors` first. Idempotent, since a cached config already holds it.
+     */
+    protected function registerErrorViews(): void
+    {
+        $paths = (array) config('view.paths', []);
+
+        if (! in_array(static::errorViewPath(), $paths, true)) {
+            config(['view.paths' => [...$paths, static::errorViewPath()]]);
+        }
+    }
+
+    /**
+     * Put the package's mail header and message after the application's own mail components,
+     * when `livewire-material.mail.components` asks for it. Off by default: it changes every
+     * Markdown mail the application sends, theme or not, and the framework reads
+     * `mail.markdown.paths` once, when the Markdown renderer is first made — after register().
+     */
+    protected function registerMailComponents(): void
+    {
+        if (! config('livewire-material.mail.components')) {
+            return;
+        }
+
+        $paths = (array) config('mail.markdown.paths', []);
+
+        if (! in_array(static::mailComponentPath(), $paths, true)) {
+            config(['mail.markdown.paths' => [...$paths, static::mailComponentPath()]]);
         }
     }