Clarify API purpose, pricing estimates and network access

[JimCollinson]

Summary

Rework the public documentation around what this service is for, rather than its internal publishing machinery:

• Explain storage cost estimates, observed-payment methodology, dates, units and limitations.
• State prominently that api.autonomi.com is a read-only information service, not a gateway for uploading, downloading or otherwise interacting with Autonomi network data.
• Preserve five signposts for actual network access: a local antd REST/gRPC daemon, daemon-backed language SDKs, daemon-backed MCP tools, the direct ant command-line client and the direct ant-core Rust client.
• Delegate changing setup, command and source details to https://developers.autonomi.com and https://developers.autonomi.com/llms.txt, with https://autonomi.com/llms.txt for broader network context. Do not maintain deep documentation paths, mutable component-branch paths or exact client commands here.
• Explain the distinction between this service's historical reference estimates and file-specific estimates or upload-payment workflows performed by client software.
• Correct machine-facing supply descriptions so cached and last-good fallback data are not described as always live.
• Move maintenance, local development, tests, deployment, publishing and governance instructions into CONTRIBUTING.md, linked as "Maintain and Contribute" at the end of the README.
• Keep root JSON and /llms.txt on the same descriptions and links without adding response fields.

The public discovery content intentionally changes. Its response structure, methods, handlers, local navigation links and operational behaviour remain unchanged. No pricing or supply calculations, CI workflows, dependencies, resources or ADR statuses change. GitHub About/homepage were already updated by Jim and are untouched. No merge or deployment is authorized by this PR preparation.

Verification

• All 44 tests pass locally, including supply/health baseline parity and shared discovery checks.
• Pinned Wrangler 4.127.0 bundle dry-run passes; no upload or deployment.
• git diff --check and python3 scripts/adr-governance.py pass.
• Rendered root JSON and /llms.txt both retain the five client-run routes and the stable developer entry points.
• Current developer portal, developer llms.txt, network llms.txt and API source destinations returned HTTP 200 when reviewed.
• Fresh Craft Review: PASS, no findings.
• Fresh clean-context review through the official Claude Code Fable route: PASS. It independently ran all 44 tests, the bundle dry-run, ADR and whitespace checks, the focused discovery tests and offline rendering, and found the intended routes discoverable without hidden context.
• Fresh advisory adversarial review: READY-WITH-NITS, with no readiness blockers. It independently reproduced the tests and relevant checks, confirmed the destinations and exact revision, and noted that the developer front door could make its daemon, SDK and direct-Rust routes more visible in future.
• GitHub CI, the green of record, passed on exact amended commit 441a4adb146fe9268090d94d52ef0846b034b88e.

Scope observations

The separate legacy DEPLOYMENT_GUIDE.md and old AGENTS.md activation/check wording remain outside this documentation change. The contributor guide identifies Cloudflare as current and documents the legacy npm development command rather than changing tooling.