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>

dev-docs/RECTOR.md

@@ -0,0 +1,94 @@
+# Rector (automated refactoring)
+
+Modernisation tool for the Crewli backend. Provides automated
+refactoring against PHP-version and Laravel-version rule sets.
+
+## Running locally
+
+- `composer rector` — DRY-RUN. Lists proposed changes, modifies
+  nothing. Default mode for safety. Exit code is 2 when suggestions
+  exist, 0 when the codebase is clean — this is Rector's convention
+  and NOT an error state.
+- `composer rector:apply` — APPLIES changes. Use only inside a
+  scoped reduction sprint with a planned set of rule-applications.
+- `composer rector:clear-cache` — clear Rector cache.
+
+Memory: 2G default. Bump to 4G if OOM.
+
+## The dry-run-then-apply model
+
+Rector configuration in `rector.php` defines the rule sets that
+SHOULD apply. `composer rector` reports what WOULD change without
+modifying code. `composer rector:apply` actually performs the
+changes.
+
+### Rules
+
+1. **Default workflow is dry-run.** Never run `composer rector:apply`
+   outside a scoped reduction sprint. Mass-applying produces
+   unreviewable PRs.
+2. **One rule-set per sprint.** Pick `SetList::DEAD_CODE` (or
+   similar) for one PR. Apply, review, regenerate baselines,
+   commit. Then move to the next set.
+3. **Run all tests + Larastan after each apply.** Rector is
+   deterministic but rule-set interactions can produce surprises
+   (e.g., `TYPE_DECLARATION` may surface new Larastan errors that
+   were previously hidden by dynamic typing).
+
+## Currently configured rule sets
+
+PHP language:
+- `withPhpSets(php82: true)` — language features up to PHP 8.2
+
+Quality:
+- `SetList::CODE_QUALITY`
+- `SetList::DEAD_CODE`
+- `SetList::EARLY_RETURN`
+- `SetList::TYPE_DECLARATION`
+- `SetList::PRIVATIZATION`
+
+Laravel:
+- `LaravelSetList::LARAVEL_CODE_QUALITY`
+- `LaravelSetList::LARAVEL_COLLECTION`
+
+**Not yet enabled** (deferred to specific reduction sprints):
+- `LaravelLevelSetList::UP_TO_LARAVEL_*` — disruptive bulk upgrades
+- `SetList::NAMING` — reformats variable names; high churn
+- `SetList::INSTANCEOF` — substantial logic changes
+
+Add a set during a reduction sprint by editing `rector.php` and
+running `composer rector` (dry-run) before applying.
+
+## Adding skip-rules
+
+If a specific rule produces incorrect changes for the project, add
+to `withSkip([...])` in `rector.php`:
+
+```php
+->withSkip([
+    SomeSpecificRule::class => [
+        __DIR__ . '/app/path/to/file.php',
+    ],
+])
+```
+
+Document the skip with a code comment in `rector.php` explaining
+why the rule is bypassed for that path.
+
+## Relationship to Larastan
+
+Different concerns:
+- **Larastan**: "this code is wrong" (types, null-safety, missing
+  methods)
+- **Rector**: "this code can be modernised" (PHP version idioms,
+  Laravel idioms, dead code, early-return patterns)
+
+Both run on the same codebase. After a Rector apply-sprint,
+regenerate the Larastan baseline — Rector changes often resolve
+Larastan errors automatically.
+
+## CI integration
+
+Not enabled yet. When added, `composer rector` (dry-run) becomes
+a non-blocking PR comment that surfaces suggested modernisations.
+Apply happens manually, never automatically in CI.