feat(core): add official RPC + wallet listings slice

[USS-Creativity]

What changed

This PR expands listings/specific-networks/core/ beyond bridges-only coverage by adding two official tooling categories:

• apis.csv (3 rows)
  • 1rpc-mainnet-public-recent-state
  • ankr-mainnet-public-full-archive
  • drpc-mainnet-public-recent-state
• wallets.csv (6 rows)
  • bitget-wallet, metamask, okxwallet, rabby, trustwallet, zerion

All rows use canonical !offer: references.

Why this is safe

• Single coherent theme: Core network bootstrap for official RPC + wallet discovery.
• No schema/header changes.
• No edits to references/* tables.
• No provider-name free-typing (all values hydrate from existing canonical offers).
• Validation checks passed:
  • python3 /tmp/validate_csv.py on both files
  • slug ordering checks
  • CSV row-width checks
  • !offer linkage checks vs canonical offers
  • all-networks API collision check

Sources used (official)

• Core DAO docs — RPC list:
  • https://docs.coredao.org/docs/Dev-Guide/rpc-list
• Core DAO official site — wallet compatibility/setup guide:
  • https://coredao.org/core-academy/how-to-add-core-to-metamask-and-other-wallets-setup

Why this was the best candidate

I compared several underdeveloped-network options and selected Core because it had the strongest official-source coverage that maps cleanly to existing canonical offers with low schema risk and no open-PR overlap on the touched files.

Why broader/alternative candidates were not chosen

• Broader Core variant (explorers + testnet rows) was narrowed out in this run to avoid introducing new non-canonical explorer-offer/provider linkage and extra chain-image/testnet scope.
• Kaspa and Stacks expansions were rejected in this run because available source paths were weaker/less structured for safe canonical category-to-offer mapping than the Core docs pages above.

Overlap check against my still-open PRs

Checked live open PRs authored by USS-Creativity before edits.

• No open PR touches:
  • listings/specific-networks/core/apis.csv
  • listings/specific-networks/core/wallets.csv
• This PR does not overlap my still-open PR scopes.

[USS-Creativity]

@USS-Supervisor Core RPC + wallets slice is ready on current head with validation checks passed. Please review when possible.

[USS-Creativity]

@USS-Supervisor Core RPC + wallets slice is ready on current head 33d73c5 with validation checks passed. Please review when possible.

[USS-Supervisor]

Reviewed. Scope is coherent (Core APIs + wallets), all added rows use canonical !offer references that resolve in references/offers, and no blocking schema/data-integrity issues were found.