api/v1: replace ForcedTags/InvalidTags/ValidTags with Tags

Simplifies the API by exposing a single tags field instead of three
separate fields for forced, invalid, and valid tags. The distinction
between these was an internal implementation detail that should not
be exposed in the public API.

Marks fields 18-20 as reserved to prevent field number reuse.

proto/headscale/v1/node.proto

@@ -35,7 +35,7 @@ message Node {
 
   RegisterMethod register_method = 13;
 
-  reserved 14 to 17;
+  reserved 14 to 20;
   // google.protobuf.Timestamp updated_at = 14;
   // google.protobuf.Timestamp deleted_at = 15;
 
@@ -43,14 +43,16 @@ message Node {
   // bytes endpoints      = 16;
   // bytes enabled_routes = 17;
 
-  repeated string forced_tags = 18;
-  repeated string invalid_tags = 19;
-  repeated string valid_tags = 20;
+  // Deprecated
+  // repeated string forced_tags = 18;
+  // repeated string invalid_tags = 19;
+  // repeated string valid_tags = 20;
   string given_name = 21;
   bool online = 22;
   repeated string approved_routes = 23;
   repeated string available_routes = 24;
   repeated string subnet_routes = 25;
+  repeated string tags = 26;
 }
 
 message RegisterNodeRequest {
@@ -58,27 +60,39 @@ message RegisterNodeRequest {
   string key = 2;
 }
 
-message RegisterNodeResponse { Node node = 1; }
+message RegisterNodeResponse {
+  Node node = 1;
+}
 
-message GetNodeRequest { uint64 node_id = 1; }
+message GetNodeRequest {
+  uint64 node_id = 1;
+}
 
-message GetNodeResponse { Node node = 1; }
+message GetNodeResponse {
+  Node node = 1;
+}
 
 message SetTagsRequest {
   uint64 node_id = 1;
   repeated string tags = 2;
 }
 
-message SetTagsResponse { Node node = 1; }
+message SetTagsResponse {
+  Node node = 1;
+}
 
 message SetApprovedRoutesRequest {
   uint64 node_id = 1;
   repeated string routes = 2;
 }
 
-message SetApprovedRoutesResponse { Node node = 1; }
+message SetApprovedRoutesResponse {
+  Node node = 1;
+}
 
-message DeleteNodeRequest { uint64 node_id = 1; }
+message DeleteNodeRequest {
+  uint64 node_id = 1;
+}
 
 message DeleteNodeResponse {}
 
@@ -87,18 +101,26 @@ message ExpireNodeRequest {
   google.protobuf.Timestamp expiry = 2;
 }
 
-message ExpireNodeResponse { Node node = 1; }
+message ExpireNodeResponse {
+  Node node = 1;
+}
 
 message RenameNodeRequest {
   uint64 node_id = 1;
   string new_name = 2;
 }
 
-message RenameNodeResponse { Node node = 1; }
+message RenameNodeResponse {
+  Node node = 1;
+}
 
-message ListNodesRequest { string user = 1; }
+message ListNodesRequest {
+  string user = 1;
+}
 
-message ListNodesResponse { repeated Node nodes = 1; }
+message ListNodesResponse {
+  repeated Node nodes = 1;
+}
 
 message DebugCreateNodeRequest {
   string user = 1;
@@ -107,8 +129,14 @@ message DebugCreateNodeRequest {
   repeated string routes = 4;
 }
 
-message DebugCreateNodeResponse { Node node = 1; }
+message DebugCreateNodeResponse {
+  Node node = 1;
+}
 
-message BackfillNodeIPsRequest { bool confirmed = 1; }
+message BackfillNodeIPsRequest {
+  bool confirmed = 1;
+}
 
-message BackfillNodeIPsResponse { repeated string changes = 1; }
+message BackfillNodeIPsResponse {
+  repeated string changes = 1;
+}