fix(contacts): Use full public key for contact deletion

Problem:
- meshcli's remove_contact command requires full public key
- We were sending only 12-char prefix, causing 'Unknown contact' errors
- Contacts appeared in list but couldn't be deleted

Solution:
- API now includes full_public_key in /api/contacts/detailed response
- Frontend uses full_public_key when available, falls back to prefix
- Added detailed logging to track deletion attempts

This fixes the issue where contacts (especially with last_seen=4)
could not be removed from the device.

app/routes/api.py

@@ -1219,6 +1219,7 @@ def get_contacts_detailed_api():
                 {
                     "name": "TK Zalesie Test 🦜",
                     "public_key_prefix": "df2027d3f2ef",
+                    "full_public_key": "df2027d3f2ef1a2b3c4d...",  // Full key (64 chars)
                     "type_label": "REP",
                     "path_or_mode": "Flood",
                     "last_seen": 1735429453,  // Unix timestamp from last_advert
@@ -1253,8 +1254,9 @@ def get_contacts_detailed_api():
                 # Find matching contact in detailed data
                 for full_key, details in contacts_detailed.items():
                     if full_key.lower().startswith(prefix):
-                        # Add last_seen timestamp
+                        # Add last_seen timestamp AND full public key
                         contact['last_seen'] = details.get('last_advert', None)
+                        contact['full_public_key'] = full_key
                         break
         else:
             # If detailed fetch failed, log warning but still return contacts without last_seen

app/static/js/contacts.js

@@ -1042,13 +1042,16 @@ async function confirmDelete() {
     }
 
     try {
+        // Use full public key if available, otherwise fall back to prefix
+        const selector = contactToDelete.full_public_key || contactToDelete.public_key_prefix;
+
         const response = await fetch('/api/contacts/delete', {
             method: 'POST',
             headers: {
                 'Content-Type': 'application/json'
             },
             body: JSON.stringify({
-                selector: contactToDelete.public_key_prefix  // Use prefix for reliability
+                selector: selector
             })
         });