[Feature] Add team splitter

[yeleepark]

Summary

Add a Team Splitter mini-tool for randomly dividing a list of people into fair teams.

Why

Team splitting is useful for workshops, meetings, games, study groups, reviews, and office activities. It expands oddkit into lightweight work-friendly mini-games while staying practical and local-first.

Proposed scope

• Paste or type a list of participant names
• Split by number of teams or people per team
• Shuffle participants randomly
• Show grouped team results clearly
• Re-shuffle without re-entering names
• Copy the generated teams to the clipboard
• Process everything locally in the browser

UX notes

• Keep participant input and team output visible together
• Use compact controls for team count and split mode
• Consider a simple seed or re-roll action for repeatable results later
• Suggested microcopy: // fair enough for the meeting room

Acceptance criteria

• A pasted list of names can be split into teams
• Both team-count and people-per-team modes work correctly
• Empty lines and duplicate whitespace are handled gracefully
• Results can be regenerated and copied
• No participant names are uploaded to a server