chore(j0.2): outillage qualite (lint strict, check.sh, mocktail)

- analysis_options.yaml durci (strict-casts/inference/raw-types + regles)
- tool/check.sh : format + analyze + test, garde-fou PATH
- mocktail en dev_dependencies
- README : contrat "check.sh avant de cocher une etape"
- ROADMAP : 0.2 cochee

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

analysis_options.yaml

@@ -1,28 +1,33 @@
-# This file configures the analyzer, which statically analyzes Dart code to
-# check for errors, warnings, and lints.
-#
-# The issues identified by the analyzer are surfaced in the UI of Dart-enabled
-# IDEs (https://dart.dev/tools#ides-and-editors). The analyzer can also be
-# invoked from the command line by running `flutter analyze`.
-
-# The following line activates a set of recommended lints for Flutter apps,
-# packages, and plugins designed to encourage good coding practices.
+# Analyse statique Storytime — durcissement au-dessus de flutter_lints.
+# Objectif : 0 warning sur l'ensemble du projet.
+# Pour désactiver une règle localement : // ignore: nom_de_la_regle
+# Pour désactiver une règle sur un fichier : // ignore_for_file: nom_de_la_regle
 include: package:flutter_lints/flutter.yaml
 
-linter:
-  # The lint rules applied to this project can be customized in the
-  # section below to disable rules from the `package:flutter_lints/flutter.yaml`
-  # included above or to enable additional rules. A list of all available lints
-  # and their documentation is published at https://dart.dev/lints.
-  #
-  # Instead of disabling a lint rule for the entire project in the
-  # section below, it can also be suppressed for a single line of code
-  # or a specific dart file by using the `// ignore: name_of_lint` and
-  # `// ignore_for_file: name_of_lint` syntax on the line or in the file
-  # producing the lint.
-  rules:
-    # avoid_print: false  # Uncomment to disable the `avoid_print` rule
-    # prefer_single_quotes: true  # Uncomment to enable the `prefer_single_quotes` rule
+analyzer:
+  language:
+    strict-casts: true
+    strict-inference: true
+    strict-raw-types: true
 
-# Additional information about this file can be found at
-# https://dart.dev/guides/language/analysis-options
+linter:
+  rules:
+    # --- Qualité générale ---
+    always_declare_return_types: true
+    avoid_print: true             # utiliser un logger plutôt que print
+    require_trailing_commas: true # lisibilité des arguments multi-lignes
+    prefer_const_constructors: true
+    prefer_const_declarations: true
+    prefer_final_locals: true
+    prefer_single_quotes: true    # cohérence : guillemets simples partout
+
+    # --- Robustesse ---
+    always_use_package_imports: true  # pas d'imports relatifs entre features
+    cancel_subscriptions: true
+    close_sinks: true
+    unawaited_futures: true
+
+    # --- Style Flutter ---
+    use_key_in_widget_constructors: true
+    sized_box_for_whitespace: true
+    prefer_const_constructors_in_immutables: true