feat: add RoutingService

This leverages the v2 SchemaService to manage its routing tables.

backend/protos/xyz/block/ftl/v1/schema/schema.proto

@@ -21,12 +21,6 @@ message Array {
   Type element = 2;
 }
 
-message Artefact {
-  bytes digest = 1;
-  string path = 2;
-  bool executable = 3;
-}
-
 message Bool {
   optional Position pos = 1;
 }
@@ -233,8 +227,7 @@ message ModuleRuntime {
   optional string os = 4;
   optional string arch = 5;
   optional string image = 6;
-  repeated Artefact artefacts = 7;
-  optional string deployment = 8;
+  optional string endpoint = 7;
 }
 
 message Optional {

backend/protos/xyz/block/ftl/v2alpha1/ftl.proto

@@ -51,11 +51,17 @@ message DeleteModuleResponse {}
 
 // SchemaService is the central source of truth for the FTL schema.
 service SchemaService {
-  rpc Ping(v1.PingRequest) returns (v1.PingResponse); // For now we need to use the v1 types to comply with the interface.
+  rpc Ping(v1.PingRequest) returns (v1.PingResponse) { // For now we need to use the v1 types to comply with the interface.
+    option idempotency_level = NO_SIDE_EFFECTS;
+  }
   // GetSchema returns the current full schema for the cluster.
-  rpc GetSchema(GetSchemaRequest) returns (GetSchemaResponse);
+  rpc GetSchema(GetSchemaRequest) returns (GetSchemaResponse) {
+    option idempotency_level = NO_SIDE_EFFECTS;
+  }
   // PullSchema returns a stream of module schema changes for the cluster.
-  rpc PullSchema(PullSchemaRequest) returns (stream PullSchemaResponse);
+  rpc PullSchema(PullSchemaRequest) returns (stream PullSchemaResponse) {
+    option idempotency_level = NO_SIDE_EFFECTS;
+  }
 
   // UpsertModule creates or replaces a module in the schema.
   rpc UpsertModule(UpsertModuleRequest) returns (UpsertModuleResponse);

backend/protos/xyz/block/ftl/v2alpha1/routing.proto

@@ -0,0 +1,16 @@
+syntax = "proto3";
+
+package xyz.block.ftl.v2alpha1;
+
+import "xyz/block/ftl/v1/ftl.proto";
+import "xyz/block/ftl/v1/verb.proto";
+
+option go_package = "github.com/TBD54566975/ftl/backend/protos/xyz/block/ftl/v2alpha1";
+option java_multiple_files = true;
+
+service RoutingService {
+  rpc Ping(v1.PingRequest) returns (v1.PingResponse) {
+    option idempotency_level = NO_SIDE_EFFECTS;
+  }
+  rpc Call(v1.CallRequest) returns (v1.CallResponse);
+}