docs: add README, dual license files, AGENTS.md; fix tsup DTS build

- Add README.md with full API reference and usage examples for npm publishing
- Add LICENSE-MIT and LICENSE-APACHE for dual licensing (MIT OR Apache-2.0)
- Update AGENTS.md with project instructions for AI agents
- Fix tsconfig.json: remove declaration, declarationMap, outDir, and sourceMap
  which conflicted with tsup's own DTS generation (TS5055 overwrite errors)

tsconfig.json

@@ -4,11 +4,7 @@
     "lib": ["ES2022"],
     "module": "Node16",
     "moduleResolution": "Node16",
-    "outDir": "./dist",
     "rootDir": "./src",
-    "declaration": true,
-    "declarationMap": true,
-    "sourceMap": true,
     "strict": true,
     "noUncheckedIndexedAccess": true,
     "noUnusedLocals": true,