fix: publishing contact fields and download stability (#771)

## ℹ️ Description
- Link to the related issue(s): Issue #761
- Describe the motivation and context for this change.
- This PR bundles several small fixes identified during recent testing,
covering issue #761 and related publishing/download edge cases.

## 📋 Changes Summary
- Avoid crashes in `download --ads=new` when existing local ads lack an
ID; skip those files for the “already downloaded” set and log a clear
reason.
- Harden publishing contact fields: clear ZIP before typing; tolerate
missing phone field; handle missing street/name/ZIP/location gracefully
with warnings instead of aborting.
- Improve location selection by matching full option text or the
district suffix after ` - `.
- Preserve `contact.location` in defaults (config model + regenerated
schema with example).

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

## ✅ Checklist
Before requesting a review, confirm the following:
- [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.

By submitting this pull request, I confirm that you can use, modify,
copy, and redistribute this contribution, under the terms of your
choice.


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

## Summary by CodeRabbit

## Release Notes

* **New Features**
* Added optional location field to contact configuration for specifying
city/locality details in listings.
* Enhanced contact field validation with improved error handling and
fallback mechanisms.

* **Bug Fixes**
* Ad download process now gracefully handles unpublished or manually
created ads instead of failing.

* **Documentation**
* Clarified shipping type requirements and cost configuration guidance
in README.

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

src/kleinanzeigen_bot/resources/translations.de.yaml

@@ -138,7 +138,6 @@ kleinanzeigen_bot/__init__.py:
     " -> SUCCESS: ad published with ID %s": " -> ERFOLG: Anzeige mit ID %s veröffentlicht"
     " -> SUCCESS: ad updated with ID %s": " -> ERFOLG: Anzeige mit ID %s aktualisiert"
     " -> effective ad meta:": " -> effektive Anzeigen-Metadaten:"
-    "Could not set city from location": "Stadt konnte nicht aus dem Standort gesetzt werden"
     "Press a key to continue...": "Eine Taste drücken, um fortzufahren..."
 
   update_ads:
@@ -152,6 +151,15 @@ kleinanzeigen_bot/__init__.py:
     "Unable to open condition dialog and select condition [%s]": "Zustandsdialog konnte nicht geöffnet und Zustand [%s] nicht ausgewählt werden"
     "Unable to select condition [%s]": "Zustand [%s] konnte nicht ausgewählt werden"
 
+  __set_contact_fields:
+    "Could not set contact street.": "Kontaktstraße konnte nicht gesetzt werden."
+    "Could not set contact name.": "Kontaktname konnte nicht gesetzt werden."
+    "Could not set contact location: %s": "Kontaktort konnte nicht gesetzt werden: %s"
+    "Could not set contact zipcode: %s": "Kontakt-PLZ konnte nicht gesetzt werden: %s"
+    "No city dropdown option matched location: %s": "Kein Eintrag im Orts-Dropdown passte zum Ort: %s"
+    ? "Phone number field not present on page. This is expected for many private accounts; commercial accounts may still support phone numbers."
+    : "Telefonnummernfeld auf der Seite nicht vorhanden. Dies ist bei vielen privaten Konten zu erwarten; gewerbliche Konten unterstützen Telefonnummern möglicherweise weiterhin."
+
   __upload_images:
     " -> found %s": "-> %s gefunden"
     "image": "Bild"