feat: Add Gebietsumring (potentialflächen_wind) from DB

app.js

@@ -1233,6 +1233,39 @@ document.addEventListener('DOMContentLoaded', async () => {
                 }
             }
 
+            // Gebietsumring (Potentialflächen) aus Datenbank laden
+            console.log("Lade Potentialflächen-Layer aus Datenbank...");
+            const potResp = await fetch(`/api/layers/potentialflaechen?project=${encodeURIComponent(projId)}`).catch(err => {
+                console.error("Netzwerkfehler beim Laden des Potentialflächen-Layers:", err);
+                return null;
+            });
+
+            if (potResp?.ok) {
+                const data = await potResp.json();
+                console.log(`Potentialflächen API: ${data.features ? data.features.length : 0} Features erhalten.`);
+                if (data.features && data.features.length > 0) {
+                    const potLayer = L.geoJSON(data, {
+                        style: {
+                            color: "#00aaff",
+                            weight: 2,
+                            fillOpacity: 0.1,
+                            dashArray: '5, 5'
+                        },
+                        onEachFeature: (feature, layer) => {
+                            layer.bindPopup(`<b>Gebietsumring</b>`);
+                        }
+                    });
+                    
+                    const label = "Gebietsumring (DB)";
+                    overlays[label] = potLayer;
+                    state.map.addLayer(potLayer);
+                    layerControl.addOverlay(potLayer, label);
+                }
+            } else {
+                const errorText = potResp ? await potResp.text() : "Server nicht erreichbar";
+                console.warn("Potentialflächen-Layer konnte nicht geladen werden:", errorText);
+            }
+
             // ALKIS aus Datenbank IMMER laden
             console.log("Lade ALKIS-Layer aus Datenbank...");
             const alkisResp = await fetch(`/api/layers/alkis?project=${encodeURIComponent(projId)}`).catch(err => {

server.js

@@ -492,6 +492,64 @@ app.get('/api/layers/alkis', async (req, res) => {
     }
 });
 
+// NEU: API zum Laden der Potentialflächen (Gebietsumring) als GeoJSON
+app.get('/api/layers/potentialflaechen', async (req, res) => {
+    const projectParam = req.query.project || req.query.projekt_id || req.query.projekt;
+    log(`Lade Potentialflächen-Layer aus Datenbank für Projekt: ${projectParam || 'alle'}`);
+    const client = await pool.connect();
+    try {
+        const hasAccess = await checkProjectAccess(req, projectParam, client);
+        if (!hasAccess) {
+            log(`Zugriff verweigert für Potentialflächen-Layer in Projekt: ${projectParam}`);
+            return res.status(403).json({ error: 'Keine Berechtigung für dieses Projekt.' });
+        }
+        let whereClause = '';
+        const params = [];
+        
+        if (projectParam) {
+            const projId = await resolveProjectId(client, projectParam);
+            const projName = await resolveProjectName(client, projectParam);
+            
+            whereClause = `WHERE projekt_id = $1`;
+            params.push(projectParam); // e.g. UUID
+            
+            if (projId && projId !== projectParam) {
+                whereClause += ` OR projekt_id = $${params.length + 1}`;
+                params.push(projId);
+            }
+            if (projName && projName !== projectParam && projName !== projId) {
+                whereClause += ` OR projekt_id = $${params.length + 1}`;
+                params.push(projName);
+            }
+        }
+
+        const result = await client.query(
+            `SELECT jsonb_build_object(
+                'type',     'FeatureCollection',
+                'features', COALESCE(jsonb_agg(features.feature), '[]'::jsonb)
+            )
+            FROM (
+              SELECT jsonb_build_object(
+                'type',       'Feature',
+                'geometry',   ST_AsGeoJSON(ST_Transform(geom, 4326))::jsonb,
+                'properties', jsonb_build_object(
+                    'id', id
+                )
+              ) AS feature
+              FROM geodaten."potentialflächen_wind"
+              ${whereClause}
+            ) features`,
+            params
+        );
+        res.json(result.rows[0].jsonb_build_object);
+    } catch (err) {
+        log(`FEHLER beim Laden des Potentialflächen-Layers: ${err.message}`);
+        res.status(500).json({ error: err.message });
+    } finally {
+        client.release();
+    }
+});
+
 // NEU: API zum Laden des Artennachweis-Layers als GeoJSON
 app.get('/api/layers/artennachweis', async (req, res) => {
     const projectParam = req.query.project || req.query.projekt_id || req.query.projekt;