* refactor(lee): split large modules into directories and extract tests
Split state.rs, program.rs, circuit.rs, validated_state_diff.rs,
merkle_tree, and core/program.rs into module directories with separate
test files. State tests are further split into themed files (genesis,
authenticated_transfer, circuit, claiming, etc.). Extract
authenticate_public_transaction_signers helper in validated_state_diff
to remove duplicated authentication logic.
* chore: rebuild artifacts
BREAKING CHANGE:
- Crate `nssa` renamed to `lee`; update `Cargo.toml` dependencies from `nssa = { workspace = true }` to `lee = { workspace = true }`.
- Crate `nssa_core` renamed to `lee_core`; update similarly.
- Crate `key_protocol` moved under `lee`; update `Cargo.toml` dependencies from `key_protocol = { workspace = true }` to `lee_key_protocol = { workspace = true }`.
- Type `NSSATransaction` (in `common`) renamed to `LeeTransaction`.
- Error type `nssa::error::NssaError` renamed to `lee::error::LeeError`.
- Error type `nssa_core::error::NssaCoreError` renamed to `lee_core::error::LeeCoreError`.
- All `use nssa::` and `use nssa_core::` import paths must be updated to `use lee::` and `use lee_core::` respectively.
- Guest programs must replace `write_nssa_outputs` with `write_lee_outputs`.
- The sequencer RocksDB column family for the chain state was renamed. Existing databases are incompatible and must be wiped before running the new version.
- Domain separators updated: `"NSSA_seed"` → `"LEE_seed"` (key derivation), `"NSSA/v0.2/KDF-SHA256/"` → `"LEE/v0.2/KDF-SHA256/"` (encryption KDF), `"/NSSA/v0.2/AccountId/PDA/"` →
`"/LEE/v0.2/AccountId/PDA/"` (public PDA address derivation). All previously derived keys, encrypted outputs, and public PDA addresses are invalidated.
