feat(M4): sources/pronote/ical.py — fetch, parsing et collecte des devoirs

- fetch_ical : HTTP via requests, support file:// (URI décodé),
  validation BEGIN:VCALENDAR, exceptions redactées
- get_calendar_name : extraction X-WR-CALNAME (paramètres + lignes repliées)
- parse_ical : parsing VEVENT → Lesson/SchoolEvent, détection cours
  annulé/déplacé, UID déterministe si absent, homeworks toujours vide
- collect_homeworks : deux passes (due + assigned), déduplication
  par ID, tri par (subject, text), target_date injecté
- generate_homework_id : SHA-1 12 chars (usedforsecurity=False)
- normalize_homework_text : unification whitespace/HTML/lowercase
- pre-commit : ajout de types-requests et icalendar au hook mypy

Co-authored-by: opencode/coder <coder@agents.invalid>

.pre-commit-config.yaml

@@ -26,7 +26,7 @@ repos:
         name: mypy
         entry: mypy
         language: python
-        additional_dependencies: ["mypy>=1.10.0", "pydantic>=2.0.0", "pydantic-settings>=2.0.0", "pytest>=8.0.0"]
+        additional_dependencies: ["mypy>=1.10.0", "pydantic>=2.0.0", "pydantic-settings>=2.0.0", "pytest>=8.0.0", "types-requests>=2.31.0", "icalendar>=5.0.0"]
         types: [python]
         pass_filenames: true