sky form: clear timezone field on new place pick so TZ auto-redetects from coords — TDD

selectPlace + geolocation now zero out tzInput.value & tzHint before schedulePreview, so the existing `if (!tzInput.value && data.timezone)` backfill in schedulePreview's success path actually fires when the user changes location after a saved sky exists. Without the clear, the saved/previous TZ stayed pinned & the chart was recomputed against the wrong timezone. Fix mirrored across sky.html (Dashsky), _applet-my-sky.html (My Sky applet entry form), and _sky_overlay.html (PICK SKY in-room overlay). New FT MySkyTimezoneRefreshTest.test_changing_place_refreshes_auto_detected_timezone seeds a user w. saved Baltimore/America/New_York, mocks Nominatim + sky/preview to return Camarillo + America/Los_Angeles, picks the suggestion, and asserts the TZ field updates.

Code architected by Disco DeDisco <discodedisco@outlook.com>
Git commit message Co-Authored-By:
Claude Sonnet 4.6 <noreply@anthropic.com>

src/templates/apps/gameboard/_partials/_sky_overlay.html

@@ -246,6 +246,8 @@
     placeInput.value = place.display_name;
     latInput.value   = parseFloat(place.lat).toFixed(4);
     lonInput.value   = parseFloat(place.lon).toFixed(4);
+    tzInput.value    = '';
+    tzHint.textContent = '';
     hideSuggestions();
     _saveForm();
     schedulePreview();
@@ -263,6 +265,8 @@
       (pos) => {
         latInput.value = pos.coords.latitude.toFixed(4);
         lonInput.value = pos.coords.longitude.toFixed(4);
+        tzInput.value  = '';
+        tzHint.textContent = '';
         fetch(`https://nominatim.openstreetmap.org/reverse?format=json&lat=${latInput.value}&lon=${lonInput.value}`, {
           headers: { 'User-Agent': USER_AGENT },
         })