feat(jmanus): file sandbox and upload system enhancement

[SapientialM]

Describe what this PR does / why we need it

Added file upload functionality in the extensions/shared folder for Agent use.
Added a file sandbox tool, currently supporting only file uploads, Agent file viewing, and file information retrieval.
The frontend now includes display and deletion features for shared folder contents.

Does this pull request fix one issue?

NONE

Describe how you did it

Shared Folder Support

• Problem: Users couldn't upload files when no plan was active
• Solution: Implemented a shared directory for plan-independent file uploads
• Implementation:
  • Added SHARED_DIR constant and related methods to FileSandboxManager
  • Created new API endpoints in FileSandboxController for shared file operations
  • Added shared file management UI in Input component
• Effect: Users can upload and manage files even without an active plan

Enhanced AI Agent Tool Support

• Solution: Create tool to support both plan-specific and shared file operations
• Effect: AI agents can now access and process both plan-specific and shared files

Describe how to verify it

upload the file, it will be showed.

execute this plan

{
  "planType": "simple",
  "title": "查看文件目录任务计划",
  "directResponse": false,
  "steps": [
    {
      "stepRequirement": "[DEFAULT_AGENT] 执行 sandbox 工具查看文件目录",
      "terminateColumns": null
    }
  ],
  "planId": "planTemplate-1755332797807"
}

To use this, first add the sandbox to the default_agent's toolchain.

Special notes for reviews

Note that the functionality is not yet fully refined. Additionally, the planId changes with each execution of the plan, and a method to upload files in real time to the isolated folder corresponding to the current plan has not yet been implemented.