Ghost stack 7/7 — Docs refresh onto the node-graph model

[nahiyankhan]

Stacked on #194 (Ghost stack 6/6).

The README, docs site, published package README, and CLAUDE.md still described the removed facet model — intent.yml/inventory.yml/composition.yml/validate.yml plus relay/compare/stack/ack/track/diverge/lint/verify. This refreshes all of it onto the current node-graph model and the 9-command surface, and tightens the intro.

What changed

• Root README.md — strong one-pager: thesis → the shape (graph of nodes) → install → quick start with a real node example → skill → the loop → command table.
• Published packages/ghost/README.md — rewritten onto the node model; corrected command set and library exports.
• CLAUDE.md — Architecture, Packages, CLI Commands, Public Exports, Conventions updated to the graph model.
• Docs site (apps/docs) — homepage thesis cut from ~1000 words to a tight statement; hero gains a tagline; getting-started, fingerprint-authoring, and cli-reference MDX rewritten onto nodes/surfaces with accurate flags; fixed stale tool/index cards and dead anchors.
• Regenerated CLI manifest, added a changeset.

Checks

• pnpm check (biome, typecheck, file-size, terminology, docs, manifest drift) ✅
• pnpm test ✅
• pnpm --filter ghost-docs build ✅

[nahiyankhan]

Superseded by #196. Folded this branch's docs/README refresh into the directory-tree PR: #196 now stacks on ghost/06-cleanup with this commit (ea08059) as its parent, and reconciles all docs onto the final directory-tree model (the surfaces.yml + nodes/*.md shape this PR described is removed). The command-set refresh, the extra files (packages/ghost/README.md, tools/docs pages, hero), and the changeset are all preserved in #196.