suggest tags based on device location too!

lib/routes/transaction_page.dart

@@ -110,6 +110,12 @@ class _TransactionPageState extends State<TransactionPage> {
   Geo? _geo;
   bool _geoHandpicked = false;
 
+  /// Device's current location, fetched independently of [_geo].
+  ///
+  /// Used to surface nearby tag suggestions even when editing an existing
+  /// transaction whose saved location differs from where the user is now.
+  Geo? _deviceGeo;
+
   bool locationFailed = false;
 
   dynamic error;
@@ -242,9 +248,9 @@ class _TransactionPageState extends State<TransactionPage> {
 
     _mapController = enableGeo ? MapController() : null;
 
-    if (widget.isNewTransaction) {
-      tryFetchLocation();
+    tryFetchLocation();
 
+    if (widget.isNewTransaction) {
       SchedulerBinding.instance.addPostFrameCallback((timeStamp) {
         _orchestrateFlow(transactionEntryFlow);
       });
@@ -445,6 +451,7 @@ class _TransactionPageState extends State<TransactionPage> {
                         selectedTags: _selectedTags,
                         onTagsChanged: onTagsChanged,
                         location: _geo,
+                        deviceLocation: _deviceGeo,
                       ),
                       DescriptionSection(
                         value: _descriptionMarkdown,
@@ -654,20 +661,25 @@ class _TransactionPageState extends State<TransactionPage> {
   void tryFetchLocation() {
     if (Platform.isLinux) return;
     if (LocalPreferences().enableGeo.get() != true) return;
-    if (LocalPreferences().autoAttachTransactionGeo.get() != true) return;
+
+    final bool autoAttach =
+        widget.isNewTransaction &&
+        LocalPreferences().autoAttachTransactionGeo.get() == true;
 
     Geolocator.getLastKnownPosition()
         .then((lastKnown) {
           if (lastKnown == null) {
             return;
           }
 
-          if (_geo != null) {
-            // In case we already have a location, don't override with less accurate one
-            return;
-          }
+          final Geo geo = Geo.fromPosition(lastKnown);
+          _deviceGeo = geo;
 
-          _geo = Geo.fromPosition(lastKnown);
+          // Only seed the transaction's location from a less-accurate
+          // last-known fix when we'd otherwise have nothing.
+          if (autoAttach && _geo == null) {
+            _geo = geo;
+          }
 
           if (mounted) setState(() => {});
         })
@@ -677,7 +689,11 @@ class _TransactionPageState extends State<TransactionPage> {
 
     Geolocator.getCurrentPosition()
         .then((current) {
-          _geo = Geo.fromPosition(current);
+          final Geo geo = Geo.fromPosition(current);
+          _deviceGeo = geo;
+          if (autoAttach) {
+            _geo = geo;
+          }
         })
         .catchError((e, stackTrace) {
           locationFailed = true;

lib/routes/transaction_page/sections/tags_section.dart

@@ -17,28 +17,44 @@ class TagsSection extends StatelessWidget {
   final VoidCallback selectTags;
   final ValueChanged<List<TransactionTag>> onTagsChanged;
 
-  /// Used for suggesting nearby tags based on the transaction's location.
+  /// Transaction's saved location, used for suggesting nearby tags.
   final Geo? location;
 
+  /// Device's current location, used in addition to [location] so that
+  /// suggestions reflect both where the transaction happened and where the
+  /// user is now (useful when editing an older transaction in a new place).
+  final Geo? deviceLocation;
+
   const TagsSection({
     super.key,
     this.selectedTags,
     required this.selectTags,
     required this.onTagsChanged,
     this.location,
+    this.deviceLocation,
   });
 
   @override
   Widget build(BuildContext context) {
-    final List<TransactionTag>? suggestedGeoTags = switch (location
-        ?.toLatLngPosition()) {
-      LatLng latLng => TransactionTagsProvider.of(
-        context,
-      ).getCloseGeoTags(latLng, exclusionList: selectedTags),
-      _ => null,
-    };
+    final TransactionTagsProvider provider = TransactionTagsProvider.of(
+      context,
+    );
+
+    final List<LatLng> suggestionOrigins = [
+      ?location?.toLatLngPosition(),
+      ?deviceLocation?.toLatLngPosition(),
+    ];
+
+    final Set<String> seen = {};
+    final List<TransactionTag> suggestedGeoTags = suggestionOrigins
+        .expand(
+          (origin) =>
+              provider.getCloseGeoTags(origin, exclusionList: selectedTags),
+        )
+        .where((tag) => seen.add(tag.uuid))
+        .toList();
 
-    final bool hasSuggestedGeoTags = suggestedGeoTags?.isNotEmpty == true;
+    final bool hasSuggestedGeoTags = suggestedGeoTags.isNotEmpty;
 
     return Section(
       title: "transaction.tags".t(context),
@@ -61,7 +77,7 @@ class TagsSection extends StatelessWidget {
                         onPressed: selectTags,
                         title: "transaction.tags.add".t(context),
                       ),
-                      ...?suggestedGeoTags?.map(
+                      ...suggestedGeoTags.map(
                         (tag) => TransactionTagChip(
                           tag: tag,
                           selected: false,