chore(release): clean up repo for v0.0.1 release

Excluded from release bundle:
- CONTEXT.md, CHANGELOG.md (agent/project working notes)
- client-app/ (React Native messenger — tracked separately)
- contracts/hello_go/ (unused standalone example)

Kept contracts/counter/ and contracts/name_registry/ as vm-test fixtures
(referenced by vm/vm_test.go; NOT production contracts).

Docs refactor:
- docs/README.md — new top-level index with cross-references
- docs/quickstart.md — rewrite around single-node as primary path
- docs/node/README.md — full rewrite, all CLI flags, schema table
- docs/api/README.md — add /api/well-known-version, /api/update-check
- docs/contracts/README.md — split native (Go) vs WASM (user-deployable)
- docs/update-system.md — new, full 5-layer update system design
- README.md — link into docs/, drop CHANGELOG/client-app references

Build-time version system (inherited from earlier commits this branch):
- node --version / client --version with ldflags-injected metadata
- /api/well-known-version with {build, protocol_version, features[]}
- Peer-version gossip on dchain/version/v1
- /api/update-check against Gitea release API
- deploy/single/update.sh with semver guard + 15-min systemd jitter

client-app/package.json

@@ -1,51 +0,0 @@
-{
-  "name": "dchain-messenger",
-  "version": "1.0.0",
-  "main": "expo-router/entry",
-  "scripts": {
-    "start": "expo start",
-    "android": "expo start --android",
-    "ios": "expo start --ios",
-    "web": "expo start --web",
-    "lint": "eslint ."
-  },
-  "dependencies": {
-    "@react-native-async-storage/async-storage": "2.2.0",
-    "class-variance-authority": "^0.7.1",
-    "clsx": "^2.1.1",
-    "expo": "~54.0.0",
-    "expo-asset": "~12.0.12",
-    "expo-camera": "~16.1.6",
-    "expo-crypto": "~14.1.4",
-    "expo-clipboard": "~8.0.8",
-    "expo-constants": "~18.0.13",
-    "expo-document-picker": "~14.0.8",
-    "expo-file-system": "~19.0.21",
-    "expo-font": "~14.0.11",
-    "expo-linking": "~8.0.11",
-    "expo-router": "~6.0.23",
-    "expo-secure-store": "~15.0.8",
-    "expo-sharing": "~14.0.8",
-    "expo-splash-screen": "~31.0.13",
-    "expo-status-bar": "~3.0.9",
-    "expo-web-browser": "~15.0.10",
-    "nativewind": "^4.1.23",
-    "react": "19.1.0",
-    "react-native": "0.81.5",
-    "react-native-reanimated": "~3.17.0",
-    "react-native-safe-area-context": "~5.6.0",
-    "react-native-screens": "~4.16.0",
-    "react-native-worklets": "~0.8.1",
-    "tailwind-merge": "^2.6.0",
-    "tailwindcss": "^3.4.17",
-    "tweetnacl": "^1.0.3",
-    "tweetnacl-util": "^0.15.1",
-    "zustand": "^5.0.3"
-  },
-  "devDependencies": {
-    "@babel/core": "^7.25.2",
-    "@types/react": "~19.1.0",
-    "babel-preset-expo": "~13.0.0",
-    "typescript": "^5.3.3"
-  }
-}