front(lint): ESLint 9 flat config + angular-eslint 19

- eslint.config.js (flat) : recommended TS + angular-eslint (ts + templates
  a11y), règles selectors app + no-unused-vars (^_ ignoré)
- script lint -> 'eslint .' (+ lint:fix), évite la résolution du builder
  Angular sous pnpm
- fix de la seule violation (variable _ inutilisée dans l'effect catalog)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

front-public/package.json

@@ -7,11 +7,10 @@
     "build": "ng build",
     "build:prod": "ng build --configuration production",
     "test": "ng test --watch=false --browsers=ChromeHeadless",
-    "lint": "ng lint"
+    "lint": "eslint .",
+    "lint:fix": "eslint . --fix"
   },
   "dependencies": {
-    "@datacat/shared": "workspace:*",
-    "@gouvfr/dsfr": "^1.13.0",
     "@angular/animations": "^19.0.0",
     "@angular/common": "^19.0.0",
     "@angular/compiler": "^19.0.0",
@@ -20,6 +19,8 @@
     "@angular/platform-browser": "^19.0.0",
     "@angular/platform-browser-dynamic": "^19.0.0",
     "@angular/router": "^19.0.0",
+    "@datacat/shared": "workspace:*",
+    "@gouvfr/dsfr": "^1.13.0",
     "rxjs": "^7.8.0",
     "tslib": "^2.8.0",
     "zone.js": "^0.15.0"
@@ -28,8 +29,12 @@
     "@angular-devkit/build-angular": "^19.0.0",
     "@angular/cli": "^19.0.0",
     "@angular/compiler-cli": "^19.0.0",
+    "@eslint/js": "^9.39.4",
     "@types/node": "^22.0.0",
+    "angular-eslint": "^19.8.1",
+    "eslint": "^9.39.4",
+    "sass": "^1.83.0",
     "typescript": "~5.8.3",
-    "sass": "^1.83.0"
+    "typescript-eslint": "^8.62.0"
   }
 }