feat(canvas): project edges from objective/constraint source

atomizer-dashboard/frontend/src/components/canvas/SpecRenderer.tsx

@@ -422,6 +422,89 @@ function SpecRendererInner({
     }
   }, [studyId, loadSpec, onStudyChange]);
 
+  // -------------------------------------------------------------------------
+  // Option A: Edge projection sync (source fields are truth)
+  // Keep canvas edges in sync when user edits objective/constraint source in panels.
+  // We only enforce Extractor -> Objective/Constraint wiring edges here.
+  // -------------------------------------------------------------------------
+
+  const isEdgeSyncingRef = useRef(false);
+
+  useEffect(() => {
+    if (!spec || !studyId) return;
+    if (isEdgeSyncingRef.current) return;
+
+    const current = spec.canvas?.edges || [];
+
+    // Compute desired extractor->objective/constraint edges from source fields
+    const desiredPairs = new Set<string>();
+
+    for (const obj of spec.objectives || []) {
+      const extractorId = obj.source?.extractor_id;
+      const outputName = obj.source?.output_name;
+      if (extractorId && outputName && extractorId !== '__UNSET__' && outputName !== '__UNSET__') {
+        desiredPairs.add(`${extractorId}__${obj.id}`);
+      }
+    }
+
+    for (const con of spec.constraints || []) {
+      const extractorId = con.source?.extractor_id;
+      const outputName = con.source?.output_name;
+      if (extractorId && outputName && extractorId !== '__UNSET__' && outputName !== '__UNSET__') {
+        desiredPairs.add(`${extractorId}__${con.id}`);
+      }
+    }
+
+    // Identify current wiring edges (ext_* -> obj_*/con_*)
+    const currentWiringPairs = new Set<string>();
+    for (const e of current) {
+      if (e.source?.startsWith('ext_') && (e.target?.startsWith('obj_') || e.target?.startsWith('con_'))) {
+        currentWiringPairs.add(`${e.source}__${e.target}`);
+      }
+    }
+
+    // Determine adds/removes
+    const toAdd: Array<{ source: string; target: string }> = [];
+    for (const key of desiredPairs) {
+      if (!currentWiringPairs.has(key)) {
+        const [source, target] = key.split('__');
+        toAdd.push({ source, target });
+      }
+    }
+
+    const toRemove: Array<{ source: string; target: string }> = [];
+    for (const key of currentWiringPairs) {
+      if (!desiredPairs.has(key)) {
+        const [source, target] = key.split('__');
+        toRemove.push({ source, target });
+      }
+    }
+
+    if (toAdd.length === 0 && toRemove.length === 0) return;
+
+    isEdgeSyncingRef.current = true;
+
+    (async () => {
+      try {
+        // Remove stale edges first
+        for (const e of toRemove) {
+          await removeEdge(e.source, e.target);
+        }
+        // Add missing edges
+        for (const e of toAdd) {
+          await addEdge(e.source, e.target);
+        }
+      } catch (err) {
+        console.error('[SpecRenderer] Edge projection sync failed:', err);
+      } finally {
+        // Small delay avoids re-entrancy storms when backend broadcasts updates
+        setTimeout(() => {
+          isEdgeSyncingRef.current = false;
+        }, 250);
+      }
+    })();
+  }, [spec, studyId, addEdge, removeEdge]);
+
   // Convert spec to ReactFlow nodes
   const nodes = useMemo(() => {
     const baseNodes = specToNodes(spec);