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

app/Models/MicropubToken.php

@@ -5,11 +5,9 @@ declare(strict_types=1);
 namespace App\Models;
 
 use Illuminate\Database\Eloquent\Attributes\Fillable;
-use Illuminate\Database\Eloquent\Attributes\Table;
 use Illuminate\Database\Eloquent\Casts\Attribute;
 use Illuminate\Database\Eloquent\Model;
 
-#[Table('micropub_tokens')]
 #[Fillable(['token_hash', 'client_id', 'me', 'scope'])]
 class MicropubToken extends Model
 {
@@ -26,11 +24,15 @@ class MicropubToken extends Model
     }
 
     /**
-     * Find the active (non-revoked) token matching a raw bearer token string.
+     * Find the active (non-revoked) token matching a raw bearer token value.
+     *
+     * Accepts mixed because callers pass request input directly, which PHP
+     * lets be an array (e.g. a client sending token[]=a) - casting that to
+     * string would throw, so anything non-string is just treated as absent.
      */
-    public static function findActive(string $rawToken): ?self
+    public static function findActive(mixed $rawToken): ?self
     {
-        if ($rawToken === '') {
+        if (! is_string($rawToken) || $rawToken === '') {
             return null;
         }