docs: reorganize into design, security, api, ops and dev; drop stale designs; refresh the diagrams [CI]

- Group docs by category with an index (docs/README.md); fix every link,
  code comment and the protocol conformance test that read docs/protocol.md.
- access.md and security.md rewritten to what is implemented: removed the
  unadopted member-proof chain, roles and recovery key that do not exist,
  the old implementation order and the budgets; gaps now carry a status.
- enrollment, deployment, api: the install flow is the static, hash-checked
  script with environment variables; no default admin.
- README and architecture: new topology and update-flow diagrams (operator
  passkey, CI signing, registry feed, auth and trust modules).

web/admin/src/pages/ReleaseKeys.tsx

@@ -7,7 +7,7 @@ import { Chip, Confirm, CopyButton, ErrorNotice, Field, useAction } from '@share
 const KEYGEN = `openssl ecparam -name prime256v1 -genkey -noout -out release.key
 openssl ec -in release.key -pubout -out release.pub.pem`
 
-const SIGN = `# manifest.json 是一行扁平的 JSON（字段见 docs/deployment.md），对它的原始字节签名：
+const SIGN = `# manifest.json 是一行扁平的 JSON（字段见 docs/ops/deployment.md），对它的原始字节签名：
 openssl dgst -sha256 -sign release.key -out manifest.sig.bin manifest.json
 base64 -w0 manifest.sig.bin > manifest.sig`