Cut over-engineering found by a repo-wide audit

- Config: auth, services, logging, queue and database only repeated the
  framework's own files and are gone; the others keep only the keys that
  differ (app version, cache serializable_classes, session cookie name,
  Markdown mail theme, the shares disk, three Octane values, Livewire's
  pagination theme and payload guards).
- Email verification is removed: User never implemented MustVerifyEmail,
  so it was never enforced, and SealShare has a single admin and no
  registration. CreateNewUser goes with it.
- FileEncryptionService::encryptFile() and generateSalt() were only used
  by tests; tests build files with encryptTestFile() in tests/Pest.php.
- The expiration options are defined once, as Share::EXPIRATIONS. "30 Days"
  now lasts 30 days instead of a calendar month, and Admin settings only
  save a default expiration that is one of the options.
- One-caller helpers are inlined, the uploader reads chunk responses with
  XHR's responseType, and starter-kit leftovers are removed.
- Docker: PHP reads the PHP_* limits from the environment itself
  (${VAR:-default} in uploads.ini); both entrypoints stop writing the ini.
  docker-compose.yml shares the app and scheduler variables through one
  anchor. The dev image installs gd for the screenshot publisher and fake
  test images.
- Development runs in Docker only: the composer dev script, concurrently,
  laravel/pail, laravel/sail, autoprefixer and the shell-quote override
  are gone.
- phpunit.xml forces the test environment with <server> entries, so tests
  run in the dev container no longer use its real database.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

app/Concerns/ProfileValidationRules.php

@@ -12,7 +12,7 @@ trait ProfileValidationRules
      *
      * @return array<string, array<int, \Illuminate\Contracts\Validation\Rule|array<mixed>|string>>
      */
-    protected function profileRules(?int $userId = null): array
+    protected function profileRules(int $userId): array
     {
         return [
             'name' => $this->nameRules(),
@@ -35,16 +35,14 @@ trait ProfileValidationRules
      *
      * @return array<int, \Illuminate\Contracts\Validation\Rule|array<mixed>|string>
      */
-    protected function emailRules(?int $userId = null): array
+    protected function emailRules(int $userId): array
     {
         return [
             'required',
             'string',
             'email',
             'max:255',
-            $userId === null
-                ? Rule::unique(User::class)
-                : Rule::unique(User::class)->ignore($userId),
+            Rule::unique(User::class)->ignore($userId),
         ];
     }
 }