chore: add copyright headers to web lib utilities

[karagozemin]

Add a per-file copyright header so ownership is visible at the file level (consistent with the root LICENSE).

Mechanical change — prepend this exact line as the first line of each file, nothing else:

// Copyright (c) 2026 Sub Rosa contributors

Add it to the following files:

• apps/web/src/lib/format.ts
• apps/web/src/lib/hex.ts
• apps/web/src/lib/round-phase.ts
• apps/web/src/lib/round-status.ts

[s6pa1rta3n-lab]

/try

I will add the required per-file copyright headers to the four web lib utility files specified in the issue description.

[Olasunkanmi975]

I have a solid understanding of the underlying architecture required for this task and am ready to start testing a solution immediately.

[D240021]

Hi! 👋

I’m currently a Computer Science student and I’m starting to get into the world of open source contributions. I’m very interested in this issue and would like to work on it to gain experience, build confidence, and expand my CV.

Could you please assign it to me? 🙂

Thank you! 🚀