feat: add rustchain_hall_of_fame — oldest/most-prized attesting hardware (Task 1 remainder)

[Vyacheslav-Tomashevskiy]

rustchain_hall_of_fame — the oldest / most-prized attesting hardware

Completes the last remaining piece of #1 Task 1. rustchain_bounties and rustchain_epoch already landed via #3074; the third tool, rustchain_hall_of_fame, was left over — this adds it, matching the existing tool pattern exactly.

What it does

Ranks the attesting miners into an antiquity leaderboard — highest antiquity multiplier first (the chain's own reward for old/rare hardware), tie-broken by the earliest first-attestation. Each entry: rank, miner id, device family, hardware type, antiquity multiplier, first-attest day, and days attesting. Live output:

RustChain hall of fame — 5 oldest / most-prized machine(s):
- #1 power8-s82… — PowerPC / PowerPC (Vintage), antiquity ×2.0 since 2026-03-29, attesting 101d.
- #2 t40-thinkp… — x86 / x86-64 (Modern), antiquity ×1.9 since 2026-05-27, attesting 42d.
- #3 claw-qinli… — Apple Silicon / Apple Silicon (Modern), antiquity ×1.2 since 2026-03-29, attesting 101d.

Keyless by design

The task mentions /hall/leaderboard, but that endpoint is auth-gated (401) — wiring it in would break the package's stated read-only / keyless safety contract. So the hall of fame is derived from the public /api/miners surface instead (it already carries antiquity_multiplier, first_attest, last_attest, device_family, hardware_type). Same data, no keys.

Consistency with the codebase

• Shared _reshape_hall helper (next to _reshape_bounty) so the sync and async clients return byte-identical output — parity test added.
• Sync + async tools, identical name/description/schema; _run/_arun never raise inside an agent loop.
• Exported summarize_hall_of_fame; README tool table + version bump (0.4.0).
• 8 new HTTP-mocked tests, full suite pytest -q → 41 passed, no network, no warnings.

Read-only / keyless, no new deps. RTC wallet: RTCd1554f0f35576faf01d386a6be1c947f560dd0b7

/claim