Architecture

┌────────────────────────────── on chain ──────────────────────────────┐
│  Pool (holds, note tree, nullifiers, fiState[])   Registry (FI leaves) │
│  Verifiers: VK_shield VK_init VK_resolve VK_reclaim VK_unshield VK_W   │
└────────────┬────────────────────────────────────────┬────────────────┘
             │ main proofs (wallet)                    │ policy proofs (FI)
┌────────────┴────────────┐                ┌───────────┴─────────────────┐
│ protocol/circuits       │                │ FI policy (3 Nargo bins,     │
│ shield, initiate,       │   context      │ generated by `weld build`)   │
│ resolve, reclaim,       │───root────────▶│ + wrapper W                  │
│ unshield                │                │ framework/weld (Rule, Ctx,   │
│ protocol/lib (gadgets)  │                │ Verdict, State, combinators, │
└─────────────────────────┘                │ #[weld::*] attributes)       │
                                            └───────────┬─────────────────┘
┌───────────────────────────────────────────────────────┴──────────────┐
│ reference/ (Rust): crypto, schema, context tree, golden world,        │
│ conformance vectors, codegen templates                                │
│ cli/ (Rust): weld build/test/register/params/codegen                  │
│ sdk-ts/, sdk-rs/: generated witness builders + pool client            │
└──────────────────────────────────────────────────────────────────────┘