Add IDE type narrowing to generated validator mixins

Make validator chains narrow types for IDEs and PHPStan without the
FluentAnalysis extension, driven entirely by the generated src/Mixins PHPDoc.

- Annotate src/Validators with #[Assurance] / #[AssuranceSubject] declaring
  each rule's assured type.
- Regenerate src/Mixins: Chain becomes generic (@template-covariant TSure);
  static entry methods narrow to Chain<concrete>; assert()/check() carry an
  unconditional @phpstan-assert TSure. Container rules (key/property/length/
  max/min) and the concrete prefix forms (nullOrIntType, keyIntType,
  allIntType) narrow; argument-wrapping and compose forms stay Chain<mixed>
  so a raw (non-fluent) Validator argument is still accepted.
- isValid() intentionally does not narrow: its only conditional form is a
  two-way guard, unsound for inexact rules on the false branch.
- Add the tests/inference static-narrowing suite (no extension config) and
  run it in CI; scope the phpstan/phpcs accommodations for generated mixins.

Author: alganet

.github/workflows/ci-code.yml

@@ -27,6 +27,7 @@ jobs:
 
       - run: composer phpunit
       - run: composer pest
+      - run: composer inference
 
   code-coverage:
     name: Code Coverage

composer.json

@@ -5,6 +5,8 @@
     "type": "library",
     "homepage": "http://respect.github.io/",
     "license": "MIT",
+    "minimum-stability": "dev",
+    "prefer-stable": true,
     "authors": [
         {
             "name": "Respect/Validation Contributors",
@@ -23,7 +25,7 @@
         "php": ">=8.5",
         "psr/container": "^2.0",
         "respect/config": "^3.0",
-        "respect/fluent": "^2.0",
+        "respect/fluent": "^3.0",
         "respect/parameter": "^3.0",
         "respect/string-formatter": "^1.7",
         "respect/stringifier": "^3.0",
@@ -45,7 +47,7 @@
         "psr/http-message": "^1.0 || ^2.0",
         "ramsey/uuid": "^4",
         "respect/coding-standard": "^5.0",
-        "respect/fluentgen": "^2.0",
+        "respect/fluentgen": "^2.1",
         "sebastian/diff": "^7.0",
         "sokil/php-isocodes": "^4.2.1",
         "sokil/php-isocodes-db-only": "^4.0",
@@ -87,6 +89,7 @@
         "phpcs": "vendor/bin/phpcs",
         "phpstan": "vendor/bin/phpstan analyze",
         "phpunit": "vendor/bin/phpunit --testsuite=unit",
+        "inference": "vendor/bin/phpunit --testsuite=inference",
         "smoke-complete": "bin/console smoke-tests:check-complete",
         "spdx-lint": "bin/console lint:spdx",
         "qa": [
@@ -95,6 +98,7 @@
             "@phpstan",
             "@phpunit",
             "@pest",
+            "@inference",
             "@docs",
             "@smoke-complete"
         ]