feat: add configurable timeouts (#673)

## ℹ️ Description
- Related issues: #671, #658
- Introduces configurable timeout controls plus retry/backoff handling
for flaky DOM operations.

We often see timeouts which are note reproducible in certain
configurations. I suspect timeout issues based on a combination of
internet speed, browser, os, age of the computer and the weather.

This PR introduces a comprehensive config model to tweak timeouts.

## 📋 Changes Summary
- add TimeoutConfig to the main config/schema and expose timeouts in
README/docs
- wire WebScrapingMixin, extractor, update checker, and browser
diagnostics to honor the configurable timeouts and retries
- update translations/tests to cover the new behaviour and ensure
lint/mypy/pyright pipelines remain green

### ⚙️ Type of Change
- [ ] 🐞 Bug fix (non-breaking change which fixes an issue)
- [x] ✨ New feature (adds new functionality without breaking existing
usage)
- [ ] 💥 Breaking change (changes that might break existing user setups,
scripts, or configurations)

## ✅ Checklist
- [x] I have reviewed my changes to ensure they meet the project's
standards.
- [x] I have tested my changes and ensured that all tests pass (`pdm run
test`).
- [x] I have formatted the code (`pdm run format`).
- [x] I have verified that linting passes (`pdm run lint`).
- [x] I have updated documentation where necessary.


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Centralized, configurable timeout system for web interactions,
detection flows, publishing, and pagination.
* Optional retry with exponential backoff for operations that time out.

* **Improvements**
* Replaced fixed wait times with dynamic timeouts throughout workflows.
  * More informative timeout-related messages and diagnostics.

* **Tests**
* New and expanded test coverage for timeout behavior, pagination,
diagnostics, and retry logic.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

src/kleinanzeigen_bot/update_checker.py

@@ -49,6 +49,10 @@ class UpdateChecker:
         """
         return __version__
 
+    def _request_timeout(self) -> float:
+        """Return the effective timeout for HTTP calls."""
+        return self.config.timeouts.effective("update_check")
+
     def _get_commit_hash(self, version:str) -> str | None:
         """Extract the commit hash from a version string.
 
@@ -74,7 +78,7 @@ class UpdateChecker:
         try:
             response = requests.get(
                 f"https://api.github.com/repos/Second-Hand-Friends/kleinanzeigen-bot/releases/tags/{tag_name}",
-                timeout = 10
+                timeout = self._request_timeout()
             )
             response.raise_for_status()
             data = response.json()
@@ -97,7 +101,7 @@ class UpdateChecker:
         try:
             response = requests.get(
                 f"https://api.github.com/repos/Second-Hand-Friends/kleinanzeigen-bot/commits/{commit}",
-                timeout = 10
+                timeout = self._request_timeout()
             )
             response.raise_for_status()
             data = response.json()
@@ -148,7 +152,7 @@ class UpdateChecker:
                 # Use /releases/latest endpoint for stable releases
                 response = requests.get(
                     "https://api.github.com/repos/Second-Hand-Friends/kleinanzeigen-bot/releases/latest",
-                    timeout = 10
+                    timeout = self._request_timeout()
                 )
                 response.raise_for_status()
                 release = response.json()
@@ -160,7 +164,7 @@ class UpdateChecker:
                 # Use /releases endpoint and select the most recent prerelease
                 response = requests.get(
                     "https://api.github.com/repos/Second-Hand-Friends/kleinanzeigen-bot/releases",
-                    timeout = 10
+                    timeout = self._request_timeout()
                 )
                 response.raise_for_status()
                 releases = response.json()