[BOUNTY] GitHub Action: RustChain Mining Status Badge — 40 RTC

[dannamax]

Implements Issue #256: GitHub Action for RustChain mining status badges. Includes API endpoint and complete GitHub Action.

[liu971227-sys]

Blocking findings:

1. Docs/runtime mismatch remains for Beacon Atlas endpoints.

• docs/API.md and README.md present /relay/register and /relay/ping as RustChain API endpoints.
• In this repository, those routes are not implemented in the RustChain node file (they belong to beacon-skill Atlas service).
• This causes immediate integration failures for users following the RustChain API docs.

2. /api/badge/<wallet> rejects valid short wallet IDs by policy.

• New guard: if not wallet or len(wallet) < 10.
• RustChain wallets are string IDs and existing usage/examples include short IDs; this hard minimum introduces false-invalid responses.

3. Badge query is schema-fragile and can 500 on mixed deployments.

• Query uses SELECT amount_i64 FROM balances WHERE miner_id = ? OR miner_pk = ?.
• Production/history schemas are not guaranteed to include both miner_id and miner_pk simultaneously; referencing a missing column raises SQL error and returns 500.
• Please avoid querying optional/non-guaranteed columns in a single static SQL statement unless schema migration guarantees both.

Please address these before merge.

[Scottcjn]

Closing — three issues: (1) Same destructive SECURITY.md rewrite as #335, (2) identical README/API.md changes bundled across both #335 and #337 (double-dipping), (3) bounty #256 requires a GitHub Action published to the Marketplace — this PR only adds a server endpoint (30% of requirements). The /api/badge endpoint code itself is decent, but please submit it as a focused PR without the SECURITY.md destruction and docs duplication.