[kvlonge]

Why

The README had grown into reference material, still described virtual environments and linked to the old docs site. Guides removed from docs/ when the website launched were never restored, and the bundled agent skill was still generated from the retired docs repository.

Changes

• Rewrote the README around verify, test and refactor safely, with a quick start, warehouse support levels and links to sqlbuild.com.
• Moved README reference sections into the docs: fixture columns, project Python layout, macro constants and enums, format behaviour, Snowflake cost estimates.
• Restored execution limits, raw-query diffs (including the sqb diff reference) and execution history.
• The docs skill generator now reads website/ pages and a shared sidebar.json and links to sqlbuild.com/docs; regenerated references drop removed pages.
• Updated links in three module READMEs.

Verification

• uv run pytest tests/unit/scripts/docs_skill: passed.
• make check-ci: passed (ruff, ty, strict adapter test, fensu 0 faults).
• astro build and scripts/check_links.py: 109 pages, 0 broken links.
• Public repository scan passed; one bounded review, findings fixed and verified.