fix(geoportal): load MapLibre CSS via CDN link injection + fullscreen layout

- Static CSS import doesn't work with next/dynamic + standalone output.
  Now injects a <link> tag to unpkg CDN at module load time (bulletproof).
- Geoportal is now fullscreen: map fills entire viewport below the header,
  no duplicate title/description, negative margins bleed to edges.
- Removed page-level CSS imports (no longer needed).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/modules/geoportal/components/map-viewer.tsx

@@ -2,8 +2,19 @@
 
 import { useRef, useEffect, useState, useCallback, useImperativeHandle, forwardRef } from "react";
 import maplibregl from "maplibre-gl";
-import "maplibre-gl/dist/maplibre-gl.css";
 import { cn } from "@/shared/lib/utils";
+
+/* Ensure MapLibre CSS is loaded — static import fails with next/dynamic + standalone */
+if (typeof document !== "undefined") {
+  const LINK_ID = "maplibre-gl-css";
+  if (!document.getElementById(LINK_ID)) {
+    const link = document.createElement("link");
+    link.id = LINK_ID;
+    link.rel = "stylesheet";
+    link.href = "https://unpkg.com/maplibre-gl@5.21.0/dist/maplibre-gl.css";
+    document.head.appendChild(link);
+  }
+}
 import type { BasemapId, ClickedFeature, LayerVisibility, SelectedFeature } from "../types";
 
 /* ------------------------------------------------------------------ */