Add attestation data export pipeline

[keon0711]

Summary

• Adds tools/attestation_export/rustchain_export.py for exporting miners, epochs, rewards, attestations, and balances to CSV/JSON/JSONL/Parquet.
• Supports public API mode with self-signed TLS handling and optional SQLite mode for node operators with DB snapshots.
• Documents usage, date filtering, epoch selection, and validation commands.

Refs Scottcjn/rustchain-bounties#49.

Validation

• python3 -m unittest tools/attestation_export/test_rustchain_export.py
• python3 -m py_compile tools/attestation_export/rustchain_export.py tools/attestation_export/test_rustchain_export.py
• python3 tools/bcos_spdx_check.py --base-ref origin/main
• git diff --check
• Live node export: python3 tools/attestation_export/rustchain_export.py --node-url https://50.28.86.131 --format json --output /tmp/rustchain-export-49 --epoch 179
  • Result: miners=19, epochs=1, rewards=168, attestations=19, balances=19
• CSV export smoke test: python3 tools/attestation_export/rustchain_export.py --node-url https://50.28.86.131 --format csv --output /tmp/rustchain-export-49-csv --epoch 179 --no-wallet-history
  • Result: miners=19, epochs=1, rewards=0, attestations=19, balances=19

Bounty

Target bounty: Scottcjn/rustchain-bounties#49, 25 RTC.
Payout identity if accepted: github:darlina-bounty-codex / RTC wallet RTC1410e82d545ce0b3ffd21ca83e2465a8f2c3a64e.

BCOS tier: L1 requested.

[keon0711]

Closing this as a duplicate of the existing bounty #49 submission in #6659. I missed the prior darlina-bounty-codex submission while checking the open bounty thread; keeping this open would add reviewer noise instead of improving the payout path.