fix(spots): editing a spot no longer drops its city/country tags

EditSpotPage rebuilds eventTags from scratch, so saving a spot replaced the
addressable event WITHOUT its city/country/country_code — silently losing the
region tags it had. It also meant re-saving a legacy spot could never fix a
missing tag.

Both edit pages (and both create pages) now go through the shared
reverseGeocodeRegions()/pushRegionTags() helper, so region tags are re-derived
on every save. Re-saving a legacy spot now tags it.

Docs: AGENTS.md (any page that republishes an addressable event must
re-derive or preserve its region tags).

AGENTS.md

@@ -867,14 +867,23 @@ session with **no other memory of this project**. So:
     the stats can't know about reports without querying them).
 - **Reverse geocoding hits Nominatim — disclosed (2026-10-01).**
   `src/lib/geocodeRegions.ts` (`reverseGeocodeRegions` / `pushRegionTags`) is the
-  **single source of truth**, used by **spot create, shop create and shop edit**;
+  **single source of truth**, used by **spot create, spot edit, shop create and
-  it fills `city`/`country`/`country_code` via
+  shop edit**; it fills `city`/`country`/`country_code` via
   `nominatim.openstreetmap.org/reverse?lat=…&lon=…` (`Accept-Language: en`) and
   **never throws** (a geocoder outage can't block a publish). Nominatim **sees the
   creator's IP** and was missing from `/privacy`'s "servers that see your IP"
   list — now disclosed as "Spot/shop geocoding". Coordinates are the **pin you
   placed**, never the device's live GPS. ⚠️ Any new outbound call that receives
   coordinates must be added to `/privacy` in the same change.
+  ⚠️ **`EditSpotPage` used to DROP region tags (fixed 2026-10-01):** like
+  `EditShopPage` it rebuilds `eventTags` from scratch, so any `city`/`country`/
+  `country_code` the spot already had were silently lost on save (the new
+  addressable event replaced the old one without them). Both edit pages now
+  `reverseGeocodeRegions()` on save. **Any page that republishes an addressable
+  event must re-derive or preserve its region tags** — check this whenever a new
+  editor is added. Related: spots created before the tags existed stay
+  "Uncategorised" in `/stats` until they're re-saved (only the author can update
+  an addressable event).
 - **NIP-05 names — `you@skate-spots.org` (2026-09-28):** SkateSpots hands out
   free handles so a new skater has a human name from minute one. The registry is
   the Netlify Function **`netlify/functions/nip05.mjs`**

src/pages/EditSpotPage.tsx

@@ -17,6 +17,7 @@ import { LoginArea } from '@/components/auth/LoginArea';
 import { PhotoDropzone } from '@/components/PhotoDropzone';
 import { TagInput } from '@/components/TagInput';
 import { SKATE_SPOT_KIND } from '@/lib/types';
+import { reverseGeocodeRegions, pushRegionTags } from '@/lib/geocodeRegions';
 import { spotCategories, MAX_TAGS, shelterOptions, DEFAULT_SHELTER, SHELTERED_VALUES, type ShelterType } from '@/lib/skateTags';
 import { cn } from '@/lib/utils';
 import {
@@ -232,6 +233,12 @@ export default function EditSpotPage() {
       // Generate geohash from coordinates (7 chars = ~153m precision)
       const geohash = ngeohash.encode(lat, lng, 7);
 
+      // Best-effort reverse geocode → city/country/country_code. Re-run on edit
+      // so moving a spot updates its region, AND so a legacy spot that has no
+      // tags gets them the next time it's saved. (This page rebuilds tags from
+      // scratch, so without this it silently DROPPED any existing region tags.)
+      const geo = await reverseGeocodeRegions(lat, lng);
+
       // Build event tags - use the same identifier to update the addressable event
       const eventTags: string[][] = [
         ['d', spot.identifier],
@@ -243,6 +250,7 @@ export default function EditSpotPage() {
         ['lon', lng.toString()],
         ['alt', `Skate spot: ${title.trim()}`],
       ];
+      pushRegionTags(eventTags, geo);
 
       if (location.trim()) {
         eventTags.push(['location', location.trim()]);