Add text sanitization and max length validation

[Alvi24-hub]

Currently, whitespace-only inputs pass validation and extremely long texts may crash the API.

[Alvi24-hub]

@Userunknown84 assign this issue to me under SSoC2026

[shashankashekharnayak2006-stack]

@Alvi24-hub Approach?

[Alvi24-hub]

@shashankashekharnayak2006-stack Use .strip() to remove leading/trailing whitespace. Add a configurable MAX_TEXT_LENGTH environment variable (default 1000 characters)

[shashankashekharnayak2006-stack]

ok take it @Alvi24-hub deadline tommorrow eod

[Alvi24-hub]

@shashankashekharnayak2006-stack pls add the SSoC labels and assign it to me