Update wiring diagram maker: formboard router + frontend

Backend formboard router and frontend (canvas, formboard, connector library,
app/api, index/css) updates. Ignore *.log.

backend/app/routers/formboard.py

@@ -54,41 +54,87 @@ def get_layout(diagram_id: int, db: Session = Depends(get_db)):
 
 @router.post("/{diagram_id}/sync")
 def sync_from_diagram(diagram_id: int, db: Session = Depends(get_db)):
-    """Import all devices from the main diagram as connector nodes.
-    Existing nodes (matched by device_id) are label-synced but not moved."""
+    """Sync devices as connector nodes and build segments from wire connections.
+
+    Layout strategy:
+      - Connectors alternate above/below a central trunk line (y=100 / y=300)
+      - Segments are auto-created for each unique device-pair connected by wires,
+        with wire_ids populated so thickness reflects the bundle size.
+    Existing nodes are label-synced but not moved; existing segments are not duplicated.
+    """
     diagram = db.query(models.Diagram).filter_by(id=diagram_id).first()
     if not diagram:
         raise HTTPException(404, "Diagram not found")
 
     layout = _get_or_create(diagram_id, db)
     existing_dev_ids = {n.device_id for n in layout.nodes if n.device_id is not None}
+    dev_to_node: dict = {n.device_id: n for n in layout.nodes if n.device_id is not None}
 
     added = 0
-    x = 80
-    for dev in diagram.devices:
+    new_x = 80 + len([n for n in layout.nodes if n.device_id is not None]) * 200
+
+    for i, dev in enumerate(diagram.devices):
+        label = dev.reference or dev.label or f"Dev {dev.id}"
         if dev.id in existing_dev_ids:
-            # Keep label in sync if the node label is still the default
-            node = next((n for n in layout.nodes if n.device_id == dev.id), None)
-            if node:
-                new_label = dev.reference or dev.label or f"Dev {dev.id}"
-                if not node.label or node.label == f"Dev {dev.id}":
-                    node.label = new_label
+            node = dev_to_node[dev.id]
+            if not node.label or node.label == f"Dev {dev.id}":
+                node.label = label
+        else:
+            # Alternate connectors above (y=80) and below (y=320) the trunk
+            row_y = 80 if added % 2 == 0 else 320
+            node = models.FormboardNode(
+                layout_id=layout.id,
+                node_type="connector",
+                device_id=dev.id,
+                x=new_x, y=row_y,
+                label=label,
+            )
+            db.add(node)
+            db.flush()  # get node.id
+            dev_to_node[dev.id] = node
+            new_x += 200
+            added += 1
+
+    # Build segments from wire connections
+    # Group wires by (min_dev_id, max_dev_id) pair to avoid direction duplicates
+    from collections import defaultdict
+    pair_wires: dict = defaultdict(list)
+    for wire in diagram.wires:
+        a, b = wire.from_device_id, wire.to_device_id
+        if a and b and a != b:
+            pair_wires[(min(a, b), max(a, b))].append(wire.id)
+
+    # Find existing segments by node-pair to avoid duplicates
+    existing_seg_pairs = set()
+    for seg in layout.segments:
+        existing_seg_pairs.add((min(seg.from_node_id, seg.to_node_id),
+                                max(seg.from_node_id, seg.to_node_id)))
+
+    segs_added = 0
+    for (dev_a, dev_b), wire_ids in pair_wires.items():
+        node_a = dev_to_node.get(dev_a)
+        node_b = dev_to_node.get(dev_b)
+        if not node_a or not node_b:
             continue
-        node = models.FormboardNode(
+        pair = (min(node_a.id, node_b.id), max(node_a.id, node_b.id))
+        if pair in existing_seg_pairs:
+            continue
+        seg = models.FormboardSegment(
             layout_id=layout.id,
-            node_type="connector",
-            device_id=dev.id,
-            x=x, y=180,
-            label=dev.reference or dev.label or f"Dev {dev.id}",
+            from_node_id=node_a.id,
+            to_node_id=node_b.id,
+            wire_ids=wire_ids,
+            fitting_type="open",
         )
-        db.add(node)
-        x += 200
-        added += 1
+        db.add(seg)
+        existing_seg_pairs.add(pair)
+        segs_added += 1
 
     db.commit()
     db.refresh(layout)
     return {
         "added": added,
+        "segs_added": segs_added,
         "nodes":    [_nd(n) for n in layout.nodes],
         "segments": [_sd(s) for s in layout.segments],
     }