Prerequisite: Please merge the PR #5248 first.

Ⅰ. Describe what this PR does

This PR migrates the core framework, entry files and utility modules from the fluid-ks-extension. The specific migration content includes:

• Migrating index.ts, App.tsx, and the directories: routes/, locales/, assets/, types/, utils/
• Migrating common components under components/ (such as ClusterSelector.tsx, KVRecordInput.tsx, etc.)

Note that specific pages (pages/) and business logic are not migrated in this PR. This change introduces the basic framework, internationalization, routing, main entry and utility modules of Fluid Extension.

Ⅱ. Does this pull request fix one issue?

NONE

Ⅲ. List the added test cases (unit test/integration test) if any, please explain if no tests are needed.

No new test cases are added in this PR. The migration primarily involves core framework, entry files and common utilities without introducing new business logic.

Ⅳ. Describe how to verify it

1. Ensure that the PR feat(dashboard-ks-extension): migrate base project structure and configs #5248 has been merged
2. Run yarn install and verify that there are no errors during installation
3. Make sure you have KubeSphere version 4 installed in your environment
4. Configure the local runtime environment:
   Obtain the access address of the KubeSphere API Server (i.e., the IP and port of ks-apiserver)
   Open or create the local_config.yaml file in the configs directory and add the following configuration (replace the example URL with your actual KubeSphere API Server address):

server:
  apiServer:
    url: http://172.31.73.3:30880 # Replace with your ks-apiserver IP and port
    wsUrl: ws://172.31.73.3:30880 # Replace with your ks-apiserver IP and port

5. Run yarn dev and you will encounter errors like module not found

Due to the absence of specific pages (such as datasets, runtimes, dataloads, etc.), some route and component references may cause compilation or runtime errors (e.g., "module not found"). This is an expected phenomenon that will be fixed in subsequent PRs for page migration.

Ⅴ. Special notes for reviews

• The expected compilation/runtime errors mentioned in the verification steps are temporary and will be addressed in subsequent page migration PRs