feat: add WMS GetFeatureInfo identify support (#97)

* feat: add WMS GetFeatureInfo identify support

Enable the identify tool for WMS layers by issuing GetFeatureInfo
requests and rendering the response in the identify popup. JSON, HTML,
and plain-text info formats are supported, with a dev-server proxy to
avoid cross-origin issues.

* Address review feedback

- Compute WMS GetFeatureInfo X/Y from a small query box centered on the
  click lng/lat so identify works in rotated/pitched views
- Remove the unreachable {bbox-epsg-3857} bypass in WMS query encoding
- Limit isWmsLayer to layer.type === "wms" to match LayerPanel's canIdentify
- Read layer.source.version and switch SRS/CRS for WMS 1.1.1 vs 1.3.0
- Set FEATURE_COUNT=1 since only the first feature is displayed
- Honor a configured layer.source.infoFormat to avoid extra round-trips
- Require a URL/sourcePath before enabling identify for WMS layers
- Treat DOMException AbortError as an abort in isAbortError
- Document the dev-only WMS proxy / production CORS limitation

* Address Claude review feedback

- Guard the WMS identify .catch() with abortController.signal.aborted so a
  superseded request can no longer null the active controller or overwrite
  the current popup
- Treat an empty GeoJSON features array as a successful "no hit" instead of
  a parse failure, avoiding extra format-probe requests
- Bail out of WMS response parsing when the signal aborts after the body read
- Parse the WMS endpoint via URL so control params override pre-existing
  duplicates and land before any fragment
- Mirror stringSource trimming in LayerPanel canIdentify so blank WMS URLs
  no longer enable identify

* Address Claude review feedback

- Require a non-blank source.layers (not just a URL) before enabling WMS
  identify, so a layer missing LAYERS no longer shows an enabled button
- Sniff bare JSON arrays in addition to objects when content-type is missing
- Keep probing remaining info formats when a body arrives in an unexpected
  format instead of returning the mismatched text early
- Make WMS FEATURE_COUNT configurable via source.featureCount (default 1)

Author: giswqs

apps/geolibre-desktop/src/components/panels/LayerPanel.tsx

@@ -221,6 +221,14 @@ export function LayerPanel({
           {visibleLayers.map((layer, displayIndex) => {
             const canIdentify =
               layer.type === "geojson" ||
+              (layer.type === "wms" &&
+                typeof layer.source.layers === "string" &&
+                Boolean(layer.source.layers.trim()) &&
+                Boolean(
+                  (typeof layer.source.url === "string" &&
+                    layer.source.url.trim()) ||
+                    layer.sourcePath,
+                )) ||
               layer.type === "vector-tiles" ||
               (layer.type === "mbtiles" &&
                 layer.metadata.tileType === "vector") ||
@@ -363,14 +371,14 @@ export function LayerPanel({
                         ? identifyActive
                           ? "Deactivate identify"
                           : "Identify features"
-                        : "Identify is only available for vector layers"
+                        : "Identify is only available for vector and WMS layers"
                     }
                     aria-label={
                       canIdentify
                         ? identifyActive
                           ? "Deactivate identify"
                           : "Identify features"
-                        : "Identify is only available for vector layers"
+                        : "Identify is only available for vector and WMS layers"
                     }
                     disabled={!canIdentify}
                     onClick={(e) => {