feat(zigbee): import to pending section with edge persistence

Coordinator auto-approves to a canvas Node; routers/end devices land in
pending_devices keyed by IEEE. Discovered parent->child edges are stored
in pending_device_links so that approving a pending device later
auto-creates the Edge once both endpoints exist as canvas Nodes.

- new POST /api/v1/zigbee/import-pending (default mode in modal)
- new pending_device_links table; ieee_address on nodes + pending_devices
- pending_devices.ip migrated to nullable (table rebuild on existing DBs)
- approve / bulk-approve return auto-created edges; sidebar pushes them
  into the canvas store with bottom -> top-t handles
- ZigbeeImportModal: radio toggle pending vs canvas; reset on close
- PendingDeviceModal: zigbee badge, IEEE/LQI/vendor/model rows, services
  hidden for zigbee
- Sidebar pending row: ZIG source badge, LQI badge, friendly_name fallback
- SearchBar: null-safe IP, also searches friendly_name and ieee_address
- Tooltip trigger uses asChild to avoid nested-button hydration error

backend/app/api/routes/scan.py

@@ -11,7 +11,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.api.deps import get_current_user
 from app.core.config import settings
 from app.db.database import AsyncSessionLocal, get_db
-from app.db.models import Node, PendingDevice, ScanRun
+from app.db.models import Edge, Node, PendingDevice, PendingDeviceLink, ScanRun
 from app.schemas.nodes import NodeCreate
 from app.schemas.scan import PendingDeviceResponse, ScanRunResponse
 from app.services.scanner import request_cancel, run_scan
@@ -126,23 +126,31 @@ async def bulk_approve_devices(
     for device in devices:
         device.status = "approved"
         node = Node(
-            label=device.hostname or device.ip,
+            label=device.hostname or device.friendly_name or device.ip or "device",
             type=device.suggested_type or "generic",
             ip=device.ip,
             hostname=device.hostname,
             status="unknown",
             services=device.services or [],
+            ieee_address=device.ieee_address,
         )
         db.add(node)
         created_nodes.append(node)
     await db.flush()  # populates node.id from Python-side default before reading
     node_ids = [n.id for n in created_nodes]
     approved_device_ids = [d.id for d in devices]
+
+    all_edges: list[dict[str, str]] = []
+    for device in devices:
+        all_edges.extend(await _resolve_pending_links_for_ieee(db, device.ieee_address))
+
     await db.commit()
     return {
         "approved": len(node_ids),
         "node_ids": node_ids,
         "device_ids": approved_device_ids,
+        "edges_created": len(all_edges),
+        "edges": all_edges,
         "skipped": len(payload.device_ids) - len(node_ids),
     }
 
@@ -186,12 +194,102 @@ async def approve_device(
         hostname=node_data.hostname,
         status=node_data.status,
         services=node_data.services or [],
+        ieee_address=device.ieee_address,
     )
     db.add(node)
     await db.flush()
     node_id = node.id
+
+    edges = await _resolve_pending_links_for_ieee(db, device.ieee_address)
+
     await db.commit()
-    return {"approved": True, "node_id": node_id}
+    return {
+        "approved": True,
+        "node_id": node_id,
+        "edges_created": len(edges),
+        "edges": edges,
+    }
+
+
+async def _resolve_pending_links_for_ieee(
+    db: AsyncSession, ieee: str | None
+) -> list[dict[str, str]]:
+    """Materialize edges for any pending_device_links involving ``ieee``.
+
+    For each link where the other endpoint already exists as a canvas Node
+    (matched by ``Node.ieee_address``), create the Edge and drop the link
+    row. Links where the other endpoint is still pending are kept so they
+    can resolve when that endpoint is approved later.
+    """
+    if not ieee:
+        return []
+
+    links_q = await db.execute(
+        select(PendingDeviceLink).where(
+            (PendingDeviceLink.source_ieee == ieee)
+            | (PendingDeviceLink.target_ieee == ieee)
+        )
+    )
+    links = list(links_q.scalars().all())
+    if not links:
+        return []
+
+    # Map every relevant ieee → Node (single query).
+    other_ieees = {
+        link.target_ieee if link.source_ieee == ieee else link.source_ieee
+        for link in links
+    }
+    other_ieees.add(ieee)
+    nodes_q = await db.execute(
+        select(Node).where(Node.ieee_address.in_(other_ieees))
+    )
+    by_ieee = {n.ieee_address: n for n in nodes_q.scalars().all() if n.ieee_address}
+
+    self_node = by_ieee.get(ieee)
+    if self_node is None:
+        return []
+
+    # Pre-fetch existing edges between these node ids so we don't create dups
+    # if the user re-approves a device or had drawn the link manually.
+    candidate_node_ids = [n.id for n in by_ieee.values()]
+    existing_q = await db.execute(
+        select(Edge).where(
+            Edge.source.in_(candidate_node_ids),
+            Edge.target.in_(candidate_node_ids),
+        )
+    )
+    existing_pairs = {(e.source, e.target) for e in existing_q.scalars().all()}
+
+    created: list[dict[str, str]] = []
+    for link in links:
+        other_ieee = (
+            link.target_ieee if link.source_ieee == ieee else link.source_ieee
+        )
+        other_node = by_ieee.get(other_ieee)
+        if other_node is None:
+            continue
+        if link.source_ieee == ieee:
+            src_id, tgt_id = self_node.id, other_node.id
+        else:
+            src_id, tgt_id = other_node.id, self_node.id
+        # Skip if either direction already exists.
+        if (src_id, tgt_id) in existing_pairs or (tgt_id, src_id) in existing_pairs:
+            await db.delete(link)
+            continue
+        edge = Edge(
+            source=src_id,
+            target=tgt_id,
+            type="iot",
+            source_handle="bottom",
+            target_handle="top-t",
+        )
+        db.add(edge)
+        await db.flush()
+        existing_pairs.add((src_id, tgt_id))
+        created.append({"id": edge.id, "source": src_id, "target": tgt_id})
+        await db.delete(link)
+
+    return created
 
 
 @router.post("/pending/{device_id}/hide")