docs: update CHANGELOG.md and README.md

[fig-ai-agent]

Docs-only update. No code, no workflow files, nothing that touches CI config.

CHANGELOG.md

[2026-09-10]

• Added the PR docs(changelog): record PR #169 (pure-agent-dev) #170 entry (the changelog PR itself).
• Added a ### Fixed note recording Issue pure-agent-dev #63 closing via PR feat(deliverables): pure-agent-dev reference implementation #169 (squash 590b8615) — the issue closed from the PR's Closes #63 reference, and no .github/workflows/ file was touched, so the merge was not blocked by the App's workflows restriction.

[2026-09-08] → Notes — stale line replaced. It claimed a SHA-pin fix sat on branch fix/sha-pin-all-workflows "awaiting admin grant of the App's workflows permission". That is out of date: the permission was granted, the push still fails, and a grant is not what is blocking. The note now records the measured state instead — as of 2026-09-10, main's workflows still mix full SHAs with mutable tags:

Action ref	Count
actions/checkout@v4	17
actions/setup-python@v5	7
actions/upload-artifact@v4	6
subosito/flutter-action@v2	5
somaz94/compress-decompress@v1	5

…plus gitleaks/gitleaks-action@v2, softprops/action-gh-release@v2 and others. The note also states plainly that the fix needs write access to .github/workflows/, which the automation App is refused (refusing to allow a GitHub App to create or update workflow ... without workflows permission), so a maintainer has to apply it — and that this is why feature PRs here show red checks even when their own tests pass.

README.md

• Deliverables row refreshed. It listed (security, notebooklm, gemini-cli, gh-devops-toolkit, azure-cli, agent-skill-template, …) — some of which no longer describe the directory, and it omitted pure-agent-dev, onspace-ai, firecrawl-fastapi and manus-client. Now: "Self-contained feature suites, each with its own README, tests, and CI (e.g. pure-agent-dev, cwe1321-protection-suite, onspace-ai, …)".
• CI reality stated. Under Repository health & standards the README implied everything was green. It now says jobs fail at the Set up job step on the org's SHA-pin policy, and that a PR passing its own tests locally still shows red — pointing at the 2026-09-08 notes.

Verification

Documentation only, so the check is that every factual claim in the diff was read off the repo rather than assumed: the tag counts come from grep over main's workflow files, the referenced CONTRIBUTING.md / SECURITY.md / RELEASE.md were confirmed to exist, the [2026-09-10] section anchors on the real 09-09 heading, and the CI note was confirmed to live in the 09-08 section (the first draft of the README cross-reference pointed at 09-09 and was corrected).