fix(review): land cleanCoordinate server-side guard; surface geocode failures

Two code-review follow-ups.

cleanCoordinate() — the server-side coordinate sanitizer the design doc and
plan both describe as already shipped — had never actually been committed; it
existed only as uncommitted work in another checkout, so this branch had no
server-side validation of lat/lng at all (the blueprint fields are plain
`type: text` with no `validate:` key). Landing it here makes the spec's stated
safety net real. Also corrected its onAdminSave comment, which justified that
hook by saying the public form's lat/lng inputs are CSS-hidden and GPS-filled
— true before this feature, inverted by it. Both hooks are needed: this branch
makes /post the primary hand-entry path, not Admin2.

The geocode lookup swallowed every failure and reset the button, leaving the
DOM byte-identical to the pre-click state — a traveller on flaky mobile data
could not distinguish a failed lookup from a broken button. It now shows a
distinct hint, and checks r.ok first so a 4xx/5xx body no longer parses as
"no results" and tells the traveller their city does not exist. R8's actual
guarantee (fields untouched on failure) is preserved.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

plugins/cache-on-save/cache-on-save.php

@@ -3,6 +3,7 @@ namespace Grav\Plugin;
 
 use Grav\Common\Cache;
 use Grav\Common\Data\ValidationException;
+use Grav\Common\Page\Interfaces\PageInterface;
 use Grav\Common\Plugin;
 use RocketTheme\Toolbox\Event\Event;
 
@@ -43,6 +44,16 @@ class CacheOnSavePlugin extends Plugin
             // (priority 0) has created the page and copied the uploaded files —
             // we reorder those files, then clear the page-tree cache.
             'onFormProcessed' => ['onFormProcessed', -100],
+            // Fired by the api plugin (PagesController) on every Admin2-driven
+            // create/update/translate, right before $page->save().
+            // onFormValidationProcessed (above) does not fire for Admin2 saves,
+            // so BOTH hooks are needed to cover every path lat/lng can arrive
+            // through: this one for Admin2/API, that one for the public /post
+            // form. (Until the location-override panel shipped, the public
+            // form's lat/lng inputs were CSS-hidden and GPS-filled, making
+            // Admin2 the only realistic hand-entry route. They are now visible
+            // and directly editable, so the /post path is the primary one.)
+            'onAdminSave' => ['onAdminSave', 0],
         ];
     }
 
@@ -74,6 +85,7 @@ class CacheOnSavePlugin extends Plugin
         }
 
         $form->setData('parent', $this->resolveDailiesParent($activeTrip));
+        $this->sanitizeCoordinates($form);
 
         // One shared /post form drives both create and edit (KTD1). add-page-by-form
         // reads overwrite_mode from the /post page header's pageconfig (not form
@@ -149,6 +161,79 @@ class CacheOnSavePlugin extends Plugin
         return '/' . $trip . '/dailies';
     }
 
+    /**
+     * Strip invisible Unicode formatting characters (bidi marks, zero-width
+     * joiners, etc. — Unicode category "Cf") from a pasted lat/lng value, then
+     * validate the result is a real coordinate.
+     *
+     * Root cause this guards against: coordinates copied from a maps app can
+     * carry an invisible mark (e.g. U+200E LEFT-TO-RIGHT MARK) that neither
+     * JS `.trim()` nor PHP's numeric-string coercion strip. Twig's
+     * `number_format` filter then silently float-casts the corrupted string
+     * to 0.0 (PHP does not raise a warning), placing the entry at Null Island
+     * instead of failing loudly.
+     *
+     * Coordinates are optional (some entries intentionally have none), so a
+     * blank value cleans to '' with no error — only a non-blank value that
+     * still fails to parse as an in-range decimal after cleaning is rejected.
+     *
+     * @return string the cleaned value to write back
+     * @throws ValidationException if non-blank but still invalid after cleaning
+     */
+    private function cleanCoordinate(string $field, string $raw, float $bound): string
+    {
+        $clean = trim(preg_replace('/\p{Cf}/u', '', $raw) ?? $raw);
+        if ($clean === '') {
+            return $clean;
+        }
+        if (!is_numeric($clean) || abs((float) $clean) > $bound) {
+            throw new ValidationException(sprintf(
+                '%s "%s" is not a valid coordinate — check for stray characters from pasting.',
+                $field === 'lat' ? 'Latitude' : 'Longitude',
+                $raw
+            ));
+        }
+        return $clean;
+    }
+
+    /** Post-form entry point (see cleanCoordinate) — 'lat'/'lng' as top-level form fields. */
+    private function sanitizeCoordinates($form): void
+    {
+        foreach (['lat' => 90.0, 'lng' => 180.0] as $field => $bound) {
+            $raw = $form->value($field);
+            if (!is_string($raw)) {
+                continue;
+            }
+            $form->setData($field, $this->cleanCoordinate($field, $raw, $bound));
+        }
+    }
+
+    /**
+     * Admin2/API entry point (see cleanCoordinate) — 'header.lat'/'header.lng'
+     * on the Page object the api plugin is about to save. Fires on every
+     * create/update/translate (PagesController::create/update/translatePage),
+     * so this also re-validates already-clean values on every subsequent edit
+     * — harmless, since a clean value round-trips unchanged.
+     */
+    public function onAdminSave(Event $event): void
+    {
+        $page = $event['page'] ?? $event['object'] ?? null;
+        if (!$page instanceof PageInterface) {
+            return;
+        }
+        $header = $page->header();
+        if (!$header) {
+            return;
+        }
+        foreach (['lat' => 90.0, 'lng' => 180.0] as $field => $bound) {
+            $raw = $header->{$field} ?? null;
+            if (!is_string($raw)) {
+                continue; // unset, null, or already a native number — nothing to clean
+            }
+            $header->{$field} = $this->cleanCoordinate($field, $raw, $bound);
+        }
+    }
+
     /**
      * The photo order the user arranged in the form, sent explicitly by
      * post-form.js as a JSON array of filenames in the dedicated