Initial commit: rustytokens — native codebase indexer + MCP server

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

tests/fixtures/tsdemo/a.ts

@@ -0,0 +1,3 @@
+import { b } from "./b";
+
+export const a = 1;

tests/fixtures/tsdemo/b.ts

@@ -0,0 +1,3 @@
+import { a } from "./a";
+
+export const b = a;