refactor(orpc): simplify architecture following KISS principle

- Fix NotFount.tsx typo -> NotFound.tsx
- Restructure ORPC: server -> middlewares -> procedures -> handlers
- Remove std-env dependency and over-engineered ephemeral detection
- Add procedures.ts as middleware composition layer
- Use globalThis for DB singleton (survives HMR)
- Preserve context in middleware (fix context merge bug)
- Remove unused ORPCContextWithDb type

src/routes/__root.tsx

@@ -7,7 +7,7 @@ import {
 } from '@tanstack/react-router'
 import type { ReactNode } from 'react'
 import { ErrorComponent } from '@/components/Error'
-import { NotFoundComponent } from '@/components/NotFount'
+import { NotFoundComponent } from '@/components/NotFound'
 import { devtools as queryDevtools } from '@/integrations/tanstack-query'
 import { devtools as routerDevtools } from '@/integrations/tanstack-router'
 import appCss from '@/styles.css?url'