refactor: extract shared code from bin/ scripts and remove legacy scheduler runner

- Extract ModuleManifestLoader for standalone manifest loading (used by
  module-deactivate and ValidateCommand)
- Extract SqlStatementParser, ModuleMigrationRepository, and
  ModuleMigrationService from bin/module-migrate.php to enforce strict
  layering (SQL in repository, orchestration in service)
- Delete bin/scheduler-run.php (fully superseded by bin/console scheduler:run)
- Update docs and test fixtures to reference bin/console

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/Http/RequestContextTest.php

@@ -41,13 +41,13 @@ class RequestContextTest extends TestCase
 
         RequestContext::start([
             'channel' => 'scheduler',
-            'path' => '/bin/scheduler-run.php',
+            'path' => 'bin/console',
         ]);
 
         $context = RequestContext::context();
 
         $this->assertSame('scheduler', $context['channel']);
-        $this->assertSame('/bin/scheduler-run.php', $context['path']);
+        $this->assertSame('bin/console', $context['path']);
         $this->assertSame('POST', $context['method']);
     }
 }