Customizable account display names on the leaderboard

[skysupersonic]

Proposal: customizable account display names on the leaderboard

Problem

Accounts are identified everywhere by their BTC address, so the leaderboard,
account pages, and other surfaces show long raw addresses. A short, optional
display name would make these far more readable and give miners a bit of
identity on the board.

Proposal

Let an account set an optional display name, shown alongside its address
(never instead of it). Concretely:

• Non-unique and cosmetic. The BTC address stays the account identity and is
  always rendered, so a non-unique name can't be used to impersonate.
• Reuses existing auth. Names are set through the existing signed
  /account/metadata flow (BIP322 / wallet signMessage), which already proves
  address ownership — no new auth surface.
• Opt-in. Accounts that never set a name are completely unchanged.
• Respects privacy. Accounts marked is_private are excluded from the bulk
  name lookup.

Where it lives (two repos)

1. para — the source of truth. Store display_name in the existing
   account_metadata JSONB (no migration), validate it on /account/metadata,
   and expose a bulk GET /names (address → name). Purely backend.
2. parastats — the site. Mirror the name into the local monitored_users
   table on metadata update (exactly like is_public is mirrored today), join
   it into the leaderboard queries, render name-over-address in the board
   components, and add an owner-only "set name" field on the account page that
   signs via the connected wallet.

This keeps a single source of truth in para and needs no per-render HTTP
calls, since the leaderboard already joins monitored_users.

Open questions for maintainers

• OK with names living in para metadata + mirrored into parastats SQLite, or
  would you prefer names owned entirely by parastats?
• Name policy: proposed 24-char cap, trimmed, control characters rejected. Want
  anything stricter (profanity/homoglyph filtering, charset limits)?
• Should there be a one-time backfill so names set on para before deploy show
  up without the user re-saving (e.g. via the stats collector)?

Offer

I have working patches for both repos ready to open as PRs (backend first, since
parastats depends on the display_name field existing). Happy to adjust the
approach based on your feedback before opening them.