Make Katib UI accessible at root path (`/`) or clarify UI root path

[anishbista60]

Description:
Currently, Katib UI is served at /katib/. If a user accesses the root path (/), it responds with 404 page not found. This can be confusing, especially when using tools like k9s to port-forward, which defaults to accessing http://localhost:8080.

Additionally, the server logs do not indicate that the UI is accessible at /katib/. For example:

2026/01/31 08:06:02 Serving the frontend dir /app/build
2026/01/31 08:06:02 Serving at 0.0.0.0:8080

Users might expect the UI to be accessible at the root (/), but currently must go to /katib/.

Proposed solutions:

1. Serve the UI at root (/)

   • Update the main() handler to serve index.html at /, for example:

     http.HandleFunc("/", kuh.ServeIndex(*buildDir))

2. Clarify in documentation that the UI root path is /katib/

   • Explicitly mention that accessing / is not supported.
   • Users should always use /katib/ as the entry point.

3. Update server logs to indicate the UI path

   • Change the log message to something like:

     2026/01/31 08:39:55 Serving Katib UI at http://0.0.0.0:8080/katib/
     

Request:
Decide on one of the following:

• Support accessing the UI at root (/)
• Clarify in documentation that /katib/ is the entry point
• Update server logs to indicate the correct UI path

I would say most straight forward solution would be third one.

[github-actions]

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