feat: update check (#561)

feat(update-check): add robust update check with interval support, state management, and CLI integration

- Implement version and interval-based update checks with configurable settings
- Add CLI command `kleinanzeigen-bot update-check` for manual checks
- Introduce state file with versioning, UTC timestamps, and migration logic
- Validate and normalize intervals (1d–4w) with fallback for invalid values
- Ensure correct handling of timezones and elapsed checks
- Improve error handling, logging, and internationalization (i18n)
- Add comprehensive test coverage for config, interval logic, migration, and CLI
- Align default config, translations, and schema with new functionality
- Improve help command UX by avoiding config/log loading for `--help`
- Update documentation and README with full feature overview

pyproject.toml

@@ -47,23 +47,20 @@ dependencies = [
 
 [dependency-groups] # https://peps.python.org/pep-0735/
 dev = [
-  # security
-  "pip-audit",
-  # testing:
-  "pytest>=8.3.4",
-  "pytest-asyncio>=0.25.3",
-  "pytest-rerunfailures",
-  "pytest-cov>=6.0.0",
-  # linting:
-  "ruff",
-  "mypy",
-  "basedpyright",
-  # formatting
-  "autopep8",
-  "yamlfix",
-  # packaging:
-  "pyinstaller",
-  "platformdirs", # required by pyinstaller
+    "pip-audit",
+    "pytest>=8.3.4",
+    "pytest-asyncio>=0.25.3",
+    "pytest-rerunfailures",
+    "pytest-cov>=6.0.0",
+    "ruff",
+    "mypy",
+    "basedpyright",
+    "autopep8",
+    "yamlfix",
+    "pyinstaller",
+    "platformdirs",
+    "types-requests>=2.32.0.20250515",
+    "pytest-mock>=3.14.0",
 ]
 
 [project.urls]