refactor(contacts): Remove path_len filter from cleanup tool

Remove impractical path length filter from contact cleanup feature.
The out_path_len parameter is rarely useful as most contacts have
value -1 (no route), making this filter unpractical for real-world use.

Changes:
- Remove path_len parameter from backend API endpoints
- Remove path length input field from HTML template
- Remove path_len collection from JavaScript code
- Update documentation (CLAUDE.md, README.md)
- Simplify cleanup filter to: name, types, date field, and days

Backend changes:
- Update _filter_contacts_by_criteria() to remove path_len logic
- Remove path_len validation from both endpoints
- Update API documentation in docstrings

Frontend changes:
- Remove Path Length input section from contacts-manage.html
- Remove path_len from collectCleanupCriteria() function

Documentation changes:
- Update API endpoint descriptions in CLAUDE.md
- Update cleanup instructions in README.md
- Remove path_len from example use cases

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

README.md

@@ -28,7 +28,7 @@ A lightweight web interface for meshcore-cli, providing browser-based access to
   - **Smart filtering:** Search by name/key, filter by contact type (CLI, REP, ROOM, SENS)
   - **Activity indicators:** Visual status icons (🟢 active, 🟡 recent, 🔴 inactive) based on last advertisement
   - **GPS location:** View contact location on Google Maps (when GPS coordinates available)
-  - **Advanced cleanup tool:** Filter and remove contacts by name, type (CLI/REP/ROOM/SENS), inactivity period, and path length with preview before deletion
+  - **Advanced cleanup tool:** Filter and remove contacts by name, type (CLI/REP/ROOM/SENS), and inactivity period with preview before deletion
 - 📦 **Message archiving** - Automatic daily archiving with browse-by-date selector
 - ⚡ **Efficient polling** - Lightweight update checks every 10s, UI refreshes only when needed
 - 📡 **Network commands** - Send advertisement (advert) or flood advertisement (floodadv) for network management
@@ -486,14 +486,12 @@ The advanced cleanup tool allows you to filter and remove contacts based on mult
      - **Contact Types:** Select which types to include (CLI, REP, ROOM, SENS)
      - **Date Field:** Choose between "Last Advert" (recommended) or "Last Modified"
      - **Days of Inactivity:** Contacts inactive for more than X days (0 = ignore)
-     - **Path Length >:** Contacts with path length greater than X (0 = ignore)
 4. Click **Preview Cleanup** to see matching contacts
 5. Review the list and confirm deletion
 
 **Example use cases:**
 - Remove all REP contacts inactive for 30+ days: Select REP, set days to 30
 - Clean specific contact names: Enter partial name (e.g., "test")
-- Remove distant contacts: Set path length > 5
 
 ### Network Commands