Add admin interface for managing node tags

Implement CRUD operations for NodeTags in the admin interface:

- Add NodeTagMove schema for moving tags between nodes
- Add PUT /nodes/{public_key}/tags/{key}/move API endpoint
- Add web routes at /a/node-tags for tag management
- Create admin templates with node selector and tag management UI
- Support editing, adding, moving, and deleting tags via API calls
- Add comprehensive tests for new functionality

The interface allows selecting a node from a dropdown, viewing its
tags, and performing all CRUD operations including moving a tag
to a different node without having to delete and recreate it.

tests/test_api/test_nodes.py

@@ -158,3 +158,133 @@ class TestNodeTags:
             headers={"Authorization": "Bearer test-admin-key"},
         )
         assert response.status_code == 201  # Created
+
+
+class TestMoveNodeTag:
+    """Tests for PUT /nodes/{public_key}/tags/{key}/move endpoint."""
+
+    # 64-character public key for testing
+    DEST_PUBLIC_KEY = "xyz789xyz789xyz789xyz789xyz789xyabc123abc123abc123abc123abc123ab"
+
+    def test_move_node_tag_success(
+        self, client_no_auth, api_db_session, sample_node, sample_node_tag
+    ):
+        """Test successfully moving a tag to another node."""
+        from meshcore_hub.common.models import Node
+        from datetime import datetime, timezone
+
+        # Create a second node with 64-char public key
+        second_node = Node(
+            public_key=self.DEST_PUBLIC_KEY,
+            name="Second Node",
+            adv_type="CHAT",
+            first_seen=datetime.now(timezone.utc),
+        )
+        api_db_session.add(second_node)
+        api_db_session.commit()
+
+        response = client_no_auth.put(
+            f"/api/v1/nodes/{sample_node.public_key}/tags/{sample_node_tag.key}/move",
+            json={"new_public_key": second_node.public_key},
+        )
+        assert response.status_code == 200
+        data = response.json()
+        assert data["key"] == sample_node_tag.key
+        assert data["value"] == sample_node_tag.value
+
+        # Verify tag is no longer on original node
+        response = client_no_auth.get(
+            f"/api/v1/nodes/{sample_node.public_key}/tags/{sample_node_tag.key}"
+        )
+        assert response.status_code == 404
+
+        # Verify tag is now on new node
+        response = client_no_auth.get(
+            f"/api/v1/nodes/{second_node.public_key}/tags/{sample_node_tag.key}"
+        )
+        assert response.status_code == 200
+
+    def test_move_node_tag_source_not_found(self, client_no_auth):
+        """Test moving a tag from a non-existent node."""
+        response = client_no_auth.put(
+            "/api/v1/nodes/nonexistent123/tags/somekey/move",
+            json={"new_public_key": self.DEST_PUBLIC_KEY},
+        )
+        assert response.status_code == 404
+        assert "Source node not found" in response.json()["detail"]
+
+    def test_move_node_tag_tag_not_found(self, client_no_auth, sample_node):
+        """Test moving a non-existent tag."""
+        response = client_no_auth.put(
+            f"/api/v1/nodes/{sample_node.public_key}/tags/nonexistent/move",
+            json={"new_public_key": self.DEST_PUBLIC_KEY},
+        )
+        assert response.status_code == 404
+        assert "Tag not found" in response.json()["detail"]
+
+    def test_move_node_tag_dest_not_found(
+        self, client_no_auth, sample_node, sample_node_tag
+    ):
+        """Test moving a tag to a non-existent destination node."""
+        # 64-character nonexistent public key
+        nonexistent_key = (
+            "1111111111111111111111111111111122222222222222222222222222222222"
+        )
+        response = client_no_auth.put(
+            f"/api/v1/nodes/{sample_node.public_key}/tags/{sample_node_tag.key}/move",
+            json={"new_public_key": nonexistent_key},
+        )
+        assert response.status_code == 404
+        assert "Destination node not found" in response.json()["detail"]
+
+    def test_move_node_tag_conflict(
+        self, client_no_auth, api_db_session, sample_node, sample_node_tag
+    ):
+        """Test moving a tag when destination already has that key."""
+        from meshcore_hub.common.models import Node, NodeTag
+        from datetime import datetime, timezone
+
+        # Create second node with same tag key
+        second_node = Node(
+            public_key=self.DEST_PUBLIC_KEY,
+            name="Second Node",
+            adv_type="CHAT",
+            first_seen=datetime.now(timezone.utc),
+        )
+        api_db_session.add(second_node)
+        api_db_session.commit()
+
+        # Add the same tag key to second node
+        existing_tag = NodeTag(
+            node_id=second_node.id,
+            key=sample_node_tag.key,  # Same key
+            value="different value",
+        )
+        api_db_session.add(existing_tag)
+        api_db_session.commit()
+
+        response = client_no_auth.put(
+            f"/api/v1/nodes/{sample_node.public_key}/tags/{sample_node_tag.key}/move",
+            json={"new_public_key": second_node.public_key},
+        )
+        assert response.status_code == 409
+        assert "already exists on destination" in response.json()["detail"]
+
+    def test_move_node_tag_requires_admin(
+        self, client_with_auth, sample_node, sample_node_tag
+    ):
+        """Test that move operation requires admin auth."""
+        # Without auth
+        response = client_with_auth.put(
+            f"/api/v1/nodes/{sample_node.public_key}/tags/{sample_node_tag.key}/move",
+            json={"new_public_key": self.DEST_PUBLIC_KEY},
+        )
+        assert response.status_code == 401
+
+        # With read key (not admin)
+        response = client_with_auth.put(
+            f"/api/v1/nodes/{sample_node.public_key}/tags/{sample_node_tag.key}/move",
+            json={"new_public_key": self.DEST_PUBLIC_KEY},
+            headers={"Authorization": "Bearer test-read-key"},
+        )
+        assert response.status_code == 403