Fork @sinclair/typemap to @alkdev/typemap with @alkdev/typebox backend

- Rename package to @alkdev/typemap, update peerDeps to @alkdev/typebox
- Replace all @sinclair/typebox imports with @alkdev/typebox
- Replace @sinclair/hammer build system with standalone build.mjs
- Remove upstream-only files (.github, .vscode, design/, typemap.png)
- Update readme with fork notice and new package names
- Add fork copyright to license

test/typebox-from-valibot.ts

@@ -1,7 +1,7 @@
-import { TypeBox } from '@sinclair/typemap'
-import { TypeGuard } from '@sinclair/typebox'
+import { TypeBox } from '@alkdev/typemap'
+import { TypeGuard } from '@alkdev/typebox'
 import { Assert } from './assert'
-import * as t from '@sinclair/typebox'
+import * as t from '@alkdev/typebox'
 import * as v from 'valibot'
 
 describe('TypeBox from Valibot', () => {