feat: upgrade to @rspress/core v2 (#1)

• chore: upgrade to rspress v2

• Update rspress dependency to @rspress/core ^2.0.3
• Add React 19 dependencies for v2
• Add “type”: “module” for ESM support
• Update import from ‘rspress/config’ to ‘@rspress/core’
• Upgrade tsconfig.json to v2 standards

• fix: use import.meta.url for ESM __dirname compatibility

• chore: update

• chore: upadte

• chore: upadte

• chore: upadte