docs(readme): rewrite control-plane readme, drop marketing banner

[echobt]

Summary

Rewrite the root README.md so a human can read it without a marketing hero.

• Drop the centered badge/banner treatment and delete unused assets/banner.jpg.
• Keep CI and license badges as ordinary status links.
• One-line value prop, capability table, working ctx quickstart, then Mine (bounty 2000 / proof 8000), Validate, Architecture, Docs, Contributing, License.
• Challenge table matches config/challenges.toml and miner docs. Proof pin is linked (config/proof-pin.toml, sha256:78b614a1…), not dumped as a giant digest. Off products stay off.
• GitHub About still has the old 🧠 marketing sentence. gh repo edit CortexLM/cortex --description "…" returns HTTP 403 with this token (no Administration scope). Owner one-liner: gh repo edit CortexLM/cortex --description "Bittensor subnet control plane — bounty + proof"

Greptile

Every PR is reviewed by Greptile before merge. Config: .greptile/.

• Greptile reviewed the first revision (P2: README claimed peer cross-check before live submit). Answered: live loop is compare_bundle_bytes → maybe_submit_match; HEAD already dropped that clause. Commented @greptileai review for HEAD.
• If the bot was silent, I commented @greptileai review

Test plan

• Docs-only: miner pins still present (https://network.cortex.foundation, scripts/install-ctx.sh, ctx challenges)
• cargo run -p xtask -- external-docs-check
• cargo test -p xtask --all-targets (includes workspace README pin gate)
• CI on this PR (4 checks green). No crate changes.

Risk

None for deploy, miner CVM measurement, signature domains, or emission. README and an unused marketing image only.

Naming

I did not rename BASE_* environment variables, deployed host paths
(/opt/base, /run/base, …), GHCR baseintelligence/base package names, or
base-*-v1 cryptographic domain tags.

  

[greptile-apps]

Greptile Summary

Updates the root README into a concise operational guide for miners, validators, and contributors. The architecture summary now accurately describes validator submission without claiming that the live path performs a peer-root cross-check.

Confidence Score: 5/5

Safe to merge.

No outstanding findings remain. The previous thread was resolved without explanation by cursor[bot]. Its current README wording is accurate: it states that validators fetch, verify, recompute, and submit, without claiming that peer-root cross-checking occurs before submission.

Files Needing Attention: None.

_{Reviews (2): Last reviewed commit: "docs(readme): add features grid and mine..." | Re-trigger Greptile}

[cursor]

@greptileai review

Please re-review HEAD (100764bd). The P2/P1 on peer cross-check before submit applied to the first README revision; that clause is gone on the current Architecture one-liner.