vigil v0.2.0 — operator summaries

Everything an operator asks for in the first five minutes, all read-only.

• vigil score — one 0-100 number with per-cell detail, fix hints, and a coverage line so a partial run never looks like a pass
• vigil disk — free space, growth slope, days-to-full
• vigil keys — keypair hygiene from stat only; the file is never opened
• vigil duties — leader slots, blocks, missed slots, skip rate
• vigil rewards — inflation rewards per epoch in SOL with commission
• vigil fleet — one roll-up across every node in fleet.json

No new dependencies. Static linux amd64 + arm64.