refactor: unify tool reason requirements

.opencode/tools/memory_manager.ts

@@ -1,3 +1,4 @@
+import { learningToolReason } from "../tool-reason.js";
 import { tool } from "../tool.js";
 import { getInternalBridgeConfig } from "../internalBridge.js";
 
@@ -8,9 +9,7 @@ export default tool({
     action: tool.schema
       .enum(["add", "list", "replace", "remove"])
       .describe("Memory operation to perform."),
-    reason: tool.schema
-      .string()
-      .describe("Why this memory should be persisted for future requests."),
+    reason: learningToolReason,
     scope: tool.schema
       .string()
       .describe(