places: migrate Google Places API from legacy to Places API (New)

[Copilot]

The legacy Google Places API (maps.googleapis.com/maps/api/place) is deprecated and new API keys return REQUEST_DENIED, causing all places search and nearby queries to fail with "search failed".

Changes

• New endpoints: places.googleapis.com/v1/places:searchNearby and :searchText
• Auth: X-Goog-Api-Key header instead of key= query param
• Transport: POST with JSON body instead of GET with query params
• Field selection: X-Goog-FieldMask header to limit response payload
• Response structs: Updated to new shape — places[], displayName.text, location.latitude/longitude, primaryType, formattedAddress, nationalPhoneNumber, websiteUri

Before (legacy)

// GET https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=...&key=...
req, _ := http.NewRequest("GET", apiURL, nil)

After (Places API New)

// POST https://places.googleapis.com/v1/places:searchNearby
req, _ := http.NewRequest("POST", apiURL, bytes.NewReader(bodyBytes))
req.Header.Set("X-Goog-Api-Key", key)
req.Header.Set("X-Goog-FieldMask", googleFieldMask)

---

🔒 GitHub Advanced Security automatically protects Copilot coding agent pull requests. You can protect all pull requests by enabling Advanced Security for your repositories. Learn more about Advanced Security.