chore: update ruler docs

Signed-off-by: Dmytro Stanchiev <git@dmytros.dev>

.ruler/02-BUN-GUIDE.md

@@ -1,52 +1,9 @@
-## Bun Guidelines
+## Bun Guide
 
-**CRITICAL**: Do not assume you know full Bun APIs. For **ANY** Bun API you use, confirm them by using `bun-docs` MCP tools.
-
-Default to using Bun instead of Node.js.
-
-- Use `bun <file>` instead of `node <file>` or `ts-node <file>`
-- Use `bun test` instead of `jest` or `vitest`
-- Use `bun build <file.html|file.ts|file.css>` instead of `webpack` or `esbuild`
-- Use `bun install` instead of `npm install` or `yarn install` or `pnpm install`
-- Use `bun run <script>` instead of `npm run <script>` or `yarn run <script>` or `pnpm run <script>`
-- Use `bunx <package> <command>` instead of `npx <package> <command>`
-- Bun automatically loads .env, so don't use dotenv.
-
-### APIs
-
-- `Bun.serve()` supports WebSockets, HTTPS, and routes. Don't use `express`.
-- `bun:sqlite` for SQLite. Don't use `better-sqlite3`.
-- `Bun.redis` for Redis. Don't use `ioredis`.
-- `Bun.sql` for Postgres. Don't use `pg` or `postgres.js`.
-- `WebSocket` is built-in. Don't use `ws`.
-- Prefer `Bun.file` over `node:fs`'s readFile/writeFile
-- Bun.$`ls` instead of execa.
-
-### Testing
-
-#### Quick Start
-- Run tests: `bun test`
-- Write tests in `tests/` folder
-
-#### Test Structure
-- Use `describe` blocks to group related tests
-- Use `test` for individual test cases
-- Use `beforeEach`/`afterEach` for setup/teardown
-
-#### Assertions
-- Import: `import { test, expect, describe, beforeEach, afterEach, mock } from "bun:test";`
-- Common: `expect(value).toBe(expected)`, `expect(fn).rejects.toThrow()`
-- Async: `await expect(asyncFn()).resolves.toBe(expected)`
-
-#### Mocking
-- Mock functions: `mock(fn)`
-- Mock globals: `global.fetch = mock(...)`
-- Restore mocks in `afterEach` or `finally`
-
-#### Best Practices
-- Mock external APIs (fetch, file I/O)
-- Test error cases and edge conditions
-- Use descriptive test names
-- Clean up resources in `afterEach`
-
-For more information, read the Bun API docs in `node_modules/bun-types/docs/**.mdx`.
+- Package manager/runtime/test runner is Bun `1.3.13`.
+- Use `bun install`, `bun run <script>`, `bun test`, and `bun build`; do not add npm/yarn/pnpm scripts.
+- Prefer Bun-native runtime APIs already used in repo: `Bun.serve`, built-in `fetch`, Web APIs, and `bun:test`.
+- Keep servers framework-free. Do not introduce Express/Koa/Fastify for the adapters.
+- Bun auto-loads `.env`; do not add `dotenv`.
+- For tests, import from `bun:test` and restore mocked globals/env in `afterEach` or `finally`.
+- Root `bun test` is misleading because `bunfig.toml` sets a dummy root. Run package test paths explicitly.