🎯 What problem does this PR solve?

• React Native and Expo consumers of @qvac/rag saw SyntaxError: 'LLMChunkAdapter' not exported when loading the package, even though the export exists in source. This was bundle corruption masquerading as a missing export.
• Root cause: @qvac/rag had raw Bare-specific imports (bare-crypto, bare-fetch) in code paths that non-Bare bundlers may still try to resolve.
• The old UUID path also depended on uuid-random plus a global crypto mutation, which made import order fragile in runtimes where crypto is not already global.

📝 How does it solve it?

• Routes Bare/runtime-specific dependencies through package.json#imports:
  • #crypto → bare-crypto on Bare, node:crypto on Node, crypto shim for RN/default.
  • #fetch → bare-fetch on Bare, fetch shim for Node/RN/default.
• Updates RAG code to use #crypto / #fetch instead of raw Bare imports.
• Adds lazy shims that allow bundling to succeed and only throw QvacErrorRAG { DEPENDENCY_REQUIRED } when the missing capability is actually used.
• Adds crypto-browserify as an optional peer for browser/RN consumers that need Node-style crypto.createHash, especially HyperDB document hashing.
• Removes uuid-random and the global crypto mutation. generateId() now creates UUID v4 IDs locally using secure randomness from globalThis.crypto.getRandomValues or #crypto.randomBytes/getRandomValues, and throws clearly if neither exists.
• Updates the RAG example model path handling to use path.resolve.

🧪 How was it tested?

• npm run lint passes.
• npm run test:unit passes: 111/111 tests, 599/599 assertions.
• Added/updated unit coverage for:
  • crypto shim missing/delegated/self-referential behavior
  • fetch shim missing/delegated/default export behavior
  • UUID generation fallback when global crypto is unusable
• Bundler verification from the original shim work still applies: patched builds resolve through #crypto / #fetch instead of hard-coded bare-crypto / bare-fetch paths.