fix(geocoding): index the local place-name prefix search

UPPER("name") LIKE UPPER(?) could never use the plain index on "name",
so every local search did a full table scan over ~170k reference
rows on TaskService's single-threaded DATABASE pool. Add a generated
name_upper column with its own index and query that instead.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016okXfGz39FtQawFWDYpQ5C

src/main/java/org/icroco/pholio/infra/geocoding/GeoReferenceDatabase.java

@@ -69,9 +69,19 @@ public class GeoReferenceDatabase {
                 )
                 """);
         jdbc.execute("CREATE INDEX IF NOT EXISTS \"ix_place_lat_lon\" ON \"place\" (\"latitude\", \"longitude\")");
-        // Backs PlaceReferenceQueryService.search's prefix lookup — a plain B-tree still helps a LIKE
-        // 'x%' scan, unlike the trailing-wildcard search this table has no use case for.
+        // No longer what backs PlaceReferenceQueryService's prefix search (see ix_place_name_upper below) —
+        // kept only in case something else ever needs a plain, case-sensitive lookup on "name" itself.
         jdbc.execute("CREATE INDEX IF NOT EXISTS \"ix_place_name\" ON \"place\" (\"name\")");
+        // H2 cannot use a plain index on "name" to accelerate a predicate wrapped in UPPER("name") — it had
+        // been doing a full table scan over all ~170k rows on every search (confirmed via EXPLAIN), which
+        // is exactly what made typing/deleting in "Add a location" feel like it froze the more you typed:
+        // every settled keystroke re-scanned the whole table on TaskService's single-threaded DATABASE pool.
+        // A generated column actually stores UPPER("name") per row, so a real index can be built on it —
+        // ix_place_name_upper turns that scan into an index range lookup. IF NOT EXISTS on both statements
+        // makes this a one-time cost (computed for every existing row) the first time an already-populated
+        // database is opened after this change, never again after.
+        jdbc.execute("ALTER TABLE \"place\" ADD COLUMN IF NOT EXISTS \"name_upper\" VARCHAR(200) GENERATED ALWAYS AS (UPPER(\"name\"))");
+        jdbc.execute("CREATE INDEX IF NOT EXISTS \"ix_place_name_upper\" ON \"place\" (\"name_upper\")");
     }
 
     /** The reference database's own {@link JdbcTemplate} — never a Spring bean, see the class javadoc. */

src/main/java/org/icroco/pholio/infra/geocoding/PlaceReferenceQueryService.java

@@ -5,6 +5,7 @@ import org.springframework.jdbc.core.RowMapper;
 import org.springframework.stereotype.Component;
 
 import java.util.List;
+import java.util.Locale;
 
 /**
  * Read-only access to the reference {@code "place"} table for the Maintenance geocoding panel — the
@@ -44,6 +45,13 @@ public class PlaceReferenceQueryService {
      * Places whose name starts with {@code query} (case-insensitive), most populous first — backs the
      * "add a place" search in {@code GeoLocationEditView}. Blank input finds nothing rather than every
      * row: a fresh search field with no text yet must not dump the whole table into a dropdown.
+     *
+     * <p>Filters on {@code "name_upper"} (a generated {@code UPPER("name")} column, see
+     * {@link GeoReferenceDatabase}) rather than wrapping {@code "name"} in {@code UPPER(...)} at query
+     * time — H2 cannot use a plain index on {@code "name"} to accelerate a predicate on a function of it,
+     * so that shape was a full table scan over every one of the ~170k reference rows on every call. The
+     * query string is upper-cased here instead, in Java, so the bind parameter matches the stored column
+     * directly and the index on it actually gets used.
      */
     public List<PlaceRow> searchByNamePrefix(String query, int limit) {
         if (query.isBlank()) {
@@ -53,11 +61,11 @@ public class PlaceReferenceQueryService {
                 """
                         SELECT "id", "name", "country_code", "admin1_code", "latitude", "longitude", "population"
                         FROM "place"
-                        WHERE UPPER("name") LIKE UPPER(?) ESCAPE '\\'
+                        WHERE "name_upper" LIKE ? ESCAPE '\\'
                         ORDER BY "population" DESC NULLS LAST
                         LIMIT ?
                         """,
-                ROW_MAPPER, escapeLikeWildcards(query.strip()) + "%", limit);
+                ROW_MAPPER, escapeLikeWildcards(query.strip()).toUpperCase(Locale.ROOT) + "%", limit);
     }
 
     /** {@code _} and {@code %} are LIKE wildcards; a place name containing either must match literally. */