Fix relative paths in .agents/index.md

Updated links in index.md to use relative paths correctly.

Author: Teddy-94

.agents/index.md

@@ -8,11 +8,11 @@ TanStack.com marketing site built with TanStack Start.
 - Run `pnpm test` before commits or after significant code changes, not after every tiny edit
 - Smoke tests live outside the default `pnpm test` path and are reserved for commit-hook validation
 - Don't run builds after every change. This is a visual site; assume changes work unless reported otherwise.
-- **Typesafety is paramount.** Never cast types; fix at source instead. See [typescript.md](.agents/typescript.md).
+- **Typesafety is paramount.** Never cast types; fix at source instead. See [typescript.md](./typescript.md).
 
 ## Topic Guides
 
-- [TypeScript Conventions](.agents/typescript.md): Type inference, casting rules, generic naming
-- [TanStack Patterns](.agents/tanstack-patterns.md): Loaders, server functions, environment shaking
-- [UI Style Guide](.agents/ui-style.md): Visual design principles for 2026
-- [Workflow](.agents/workflow.md): Build commands, debugging, Playwright
+- [TypeScript Conventions](./typescript.md): Type inference, casting rules, generic naming
+- [TanStack Patterns](./tanstack-patterns.md): Loaders, server functions, environment shaking
+- [UI Style Guide](./ui-style.md): Visual design principles for 2026
+- [Workflow](./workflow.md): Build commands, debugging, Playwright