Fix CSRF exemption and array-input crash on revocation/introspection

An Opus code review of the branch caught two real bugs the test suite
structurally couldn't see:

- /revocation and /introspect were never added to bootstrap/app.php's
  CSRF except list, so both were fully broken (403) for any real
  external client, despite every feature test passing — CSRF
  verification is short-circuited entirely while running tests.
  Verified live against the running app before and after the fix, and
  added a regression test that asserts against the actual configured
  exemptions rather than relying on request-time behavior that tests
  can't exercise.

- An array-shaped `token` param (e.g. token[]=a&token[]=b) crashed
  both endpoints with a 500, since this app promotes PHP warnings
  ("Array to string conversion") to exceptions. Fixed at the shared
  root, MicropubToken::findActive(), which also closes the same latent
  hole in VerifyMicropubToken's access_token param that predates this
  branch. Verified live and covered with regression tests.

Also applied the review's lower-severity findings: added the missing
introspection_endpoint Link header and metadata test assertions,
removed the now-dead is_string($scopes) array branch in the Micropub
handlers and media controller (scope is unconditionally a string from
the DB now, this guarded against a JWT-array-claim shape that can no
longer occur), dropped a redundant #[Table] model attribute, sized
token_hash to its actual 64-char length, and removed a one-off inline
style in the admin view.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014625MfkGZ7GVdbqKme4a8L

tests/Feature/CsrfExemptionsTest.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature;
+
+use Illuminate\Foundation\Http\Middleware\PreventRequestForgery;
+use PHPUnit\Framework\Attributes\Test;
+use Tests\TestCase;
+
+class CsrfExemptionsTest extends TestCase
+{
+    /**
+     * CSRF verification is short-circuited entirely while running the test
+     * suite (see PreventRequestForgery::runningUnitTests()), so a normal
+     * feature test hitting these routes would pass even if they were never
+     * added to bootstrap/app.php's except list. Assert against the actual
+     * configured exemptions instead.
+     */
+    #[Test]
+    public function external_api_endpoints_are_exempt_from_csrf_verification(): void
+    {
+        $exemptions = $this->app->make(PreventRequestForgery::class)->getExcludedPaths();
+
+        foreach (['auth', 'token', 'revocation', 'introspect', 'api/post', 'api/media', 'micropub/places', 'webmention'] as $path) {
+            $this->assertContains($path, $exemptions);
+        }
+    }
+}

tests/Feature/HeaderLinkTest.php

@@ -20,7 +20,8 @@ class HeaderLinkTest extends TestCase
         $this->assertSame('<'.config('app.url').'/auth>; rel="authorization_endpoint"', $linkHeaders[1]);
         $this->assertSame('<'.config('app.url').'/token>; rel="token_endpoint"', $linkHeaders[2]);
         $this->assertSame('<'.config('app.url').'/revocation>; rel="revocation_endpoint"', $linkHeaders[3]);
-        $this->assertSame('<'.config('app.url').'/api/post>; rel="micropub"', $linkHeaders[4]);
-        $this->assertSame('<'.config('app.url').'/webmention>; rel="webmention"', $linkHeaders[5]);
+        $this->assertSame('<'.config('app.url').'/introspect>; rel="introspection_endpoint"', $linkHeaders[4]);
+        $this->assertSame('<'.config('app.url').'/api/post>; rel="micropub"', $linkHeaders[5]);
+        $this->assertSame('<'.config('app.url').'/webmention>; rel="webmention"', $linkHeaders[6]);
     }
 }

tests/Feature/IndieAuthTest.php

@@ -29,9 +29,10 @@ class IndieAuthTest extends TestCase
             'issuer' => config('app.url'),
             'authorization_endpoint' => route('indieauth.start'),
             'token_endpoint' => route('indieauth.token'),
+            'revocation_endpoint' => route('indieauth.revocation'),
+            'introspection_endpoint' => route('indieauth.introspection'),
+            'introspection_endpoint_auth_methods_supported' => ['Bearer'],
             'code_challenge_methods_supported' => ['S256'],
-            // 'introspection_endpoint' => 'introspection_endpoint',
-            // 'introspection_endpoint_auth_methods_supported' => ['none'],
         ]);
     }
 
@@ -795,4 +796,31 @@ class IndieAuthTest extends TestCase
         $response->assertStatus(200);
         $response->assertExactJson(['active' => false]);
     }
+
+    #[Test]
+    public function revocation_does_not_error_on_an_array_shaped_token_param(): void
+    {
+        $response = $this->post('/revocation', ['token' => ['a', 'b']]);
+
+        $response->assertStatus(200);
+    }
+
+    #[Test]
+    public function introspection_does_not_error_on_an_array_shaped_token_param(): void
+    {
+        $callerToken = resolve(TokenService::class)->getNewToken([
+            'me' => config('app.url'),
+            'client_id' => 'https://app.example.com',
+            'scope' => 'create',
+        ]);
+
+        $response = $this->post(
+            '/introspect',
+            ['token' => ['a', 'b']],
+            ['HTTP_Authorization' => 'Bearer '.$callerToken]
+        );
+
+        $response->assertStatus(200);
+        $response->assertExactJson(['active' => false]);
+    }
 }

tests/Feature/TokenServiceTest.php

@@ -71,4 +71,18 @@ class TokenServiceTest extends TestCase
             'error_description' => 'The provided token did not pass validation',
         ]);
     }
+
+    /**
+     * Request input for a "string" field can be sent as an array
+     * (e.g. token[]=a&token[]=b). Casting that to string throws in this app
+     * (warnings are promoted to exceptions), so findActive() must guard
+     * against it rather than assume its caller already validated the type.
+     */
+    #[Test]
+    public function find_active_treats_non_string_input_as_absent(): void
+    {
+        $this->assertNull(MicropubToken::findActive(['a', 'b']));
+        $this->assertNull(MicropubToken::findActive(null));
+        $this->assertNull(MicropubToken::findActive(123));
+    }
 }