✨ Safe float + data-bar support (follow-up to #5)

[gepser]

Summary

• add support for float values in /progress/{percentage}
• add optional data-bar mode with min + max
• add optional label and barColor query params
• keep existing HTTP contract and hardening in place (GET/HEAD, cache headers, no fatal exits)
• add validation and limits:
  • numeric input checks (including NaN/Inf)
  • min/max must be provided together and max > min
  • hex validation for all colors (including barColor)
  • label length cap (64 chars)
• expand tests to cover all new paths + error conditions
• update README API docs and examples

Why

This is a safe rework of the idea from PR #5, adapted to the current codebase.
I delayed updating the project for too long that it was not possible to merely merge the PR, I'm sorry for that.
Still, I appreciate the contribution @mgiannopoulos24, and this is based on your idea and your work, so credits to you.

Validation

• mise exec -- make check ✅

Example

• ![](https://geps.dev/progress/76.5)
• ![](https://geps.dev/progress/186?label=186&min=0&max=241&barColor=4472C4)