initial scaffold

- module layout: cmd/mithril-go, internal/{aggregator,artifact,verify,networks}
- aggregator REST client, list command working against mainnet
- download/extract/verify stubbed
- no deps yet, pure stdlib

README.md

@@ -0,0 +1,42 @@
+# mithril-go
+
+Pure-Go client for the Cardano [Mithril](https://mithril.network) protocol.
+
+Mithril is Cardano's stake-based certified-snapshot system — it lets a new
+node bootstrap the chain from a cryptographically-verified snapshot
+instead of replaying every block from genesis.
+
+The official [`mithril-client`](https://github.com/input-output-hk/mithril)
+is Rust. This project is a pure-Go reimplementation that produces a single
+static binary with no runtime dependencies — useful for:
+
+- Embedding a Mithril bootstrap into Go-based Cardano tooling
+  (alongside `gouroboros`, `dingo`, and friends)
+- Running on constrained ARM/embedded targets where shipping the Rust
+  binary + its deps is overkill
+- Operators who prefer a single `go install`-able helper
+
+## Status
+
+**Early development — not usable yet.** Current state:
+
+- [x] Module scaffold, network configs, aggregator REST client
+- [x] `list` command hits the aggregator and enumerates cardano-database snapshots
+- [ ] `download` — range-chunk parallel HTTP, SHA-256 integrity, resume
+- [ ] `extract` — streamed zstd + tar decompression
+- [ ] Genesis Ed25519 verification (per-network bootstrap key)
+- [ ] STM BLS12-381 aggregate-signature verification (the hard part)
+- [ ] Incremental / ancillary artifact support
+
+## Usage (eventual)
+
+```
+mithril-go info     -network mainnet
+mithril-go list     -network mainnet
+mithril-go download -network mainnet -out ./db latest
+mithril-go verify   -network mainnet ./db
+```
+
+## License
+
+TBD