chore: install rector with accept-current-state baseline

Installs rector/rector ^2.0 (v2.4.2) + driftingly/rector-laravel
^2.0 as dev-dependencies. Configures PHP 8.2 language sets + safe
quality rule sets (CODE_QUALITY, DEAD_CODE, EARLY_RETURN,
TYPE_DECLARATION, PRIVATIZATION) + Laravel-specific sets
(LARAVEL_CODE_QUALITY, LARAVEL_COLLECTION).

Dry-run baseline: 487 rule-applications across 357 files. NO
changes applied in this commit — adoption is incremental via per-
set sprints documented in BACKLOG.md.

Top rules by volume:
  103  AddClosureVoidReturnTypeWhereNoReturnRector
   71  AddArrowFunctionReturnTypeRector
   51  AppToResolveRector
   34  ConvertStaticToSelfRector
   27  ReadOnlyClassRector
   18  NullToStrictStringFuncCallArgRector
   16  ReturnBinaryOrToEarlyReturnRector
   16  MakeModelAttributesAndScopesProtectedRector
   13  RemoveUnusedVariableAssignRector
   13  OptionalToNullsafeOperatorRector
   13  FlipTypeControlToUseExclusiveTypeRector

Composer scripts:
  - composer rector              — DRY-RUN (default)
  - composer rector:apply        — apply changes
  - composer rector:clear-cache  — clear Rector cache

Dry-run exits with code 2 when suggestions exist (Rector convention,
not an error state). Apply-mode exits 0 on clean runs.

Documentation: /dev-docs/RECTOR.md added; CLAUDE.md updated.

Backlog: per-set application sprints seeded
(TECH-RECTOR-01..05 + TECH-RECTOR-CI). DEAD_CODE (smallest scope)
and TYPE_DECLARATION (biggest volume, will help reduce Larastan
baseline) are the natural first two.

Disruptive sets deliberately deferred:
  - LaravelLevelSetList::UP_TO_LARAVEL_* — broad bulk upgrades
  - SetList::NAMING — high-churn variable renames
  - SetList::INSTANCEOF — substantial logic changes

Memory limit 2G (dry-run completed within it).

No production behavior change. No code modified — Rector ran
dry-run only.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

api/composer.json

@@ -18,6 +18,7 @@
         "spatie/laravel-permission": "^7.2"
     },
     "require-dev": {
+        "driftingly/rector-laravel": "^2.0",
         "fakerphp/faker": "^1.23",
         "larastan/larastan": "^3.0",
         "laravel/pail": "^1.2.2",
@@ -25,7 +26,8 @@
         "laravel/sail": "^1.41",
         "mockery/mockery": "^1.6",
         "nunomaduro/collision": "^8.6",
-        "phpunit/phpunit": "^11.5.3"
+        "phpunit/phpunit": "^11.5.3",
+        "rector/rector": "^2.0"
     },
     "autoload": {
         "psr-4": {
@@ -59,6 +61,9 @@
         "analyse": "vendor/bin/phpstan analyse --memory-limit=2G",
         "analyse:baseline": "vendor/bin/phpstan analyse --generate-baseline --memory-limit=2G",
         "analyse:clear-cache": "vendor/bin/phpstan clear-result-cache",
+        "rector": "vendor/bin/rector process --dry-run --memory-limit=2G",
+        "rector:apply": "vendor/bin/rector process --memory-limit=2G",
+        "rector:clear-cache": "vendor/bin/rector --clear-cache",
         "post-autoload-dump": [
             "Illuminate\\Foundation\\ComposerScripts::postAutoloadDump",
             "@php artisan package:discover --ansi"