chore: fork tmsqlite from gordian core

While the repository was private, using tmsqlite as a nested module was
much simpler than dealing with separate private Go modules.

Also add a better README.

README.md

@@ -1,78 +1,25 @@
-# Gordian
+# tmsqlite
 
-Gordian is a modular, [Byzantine-fault-tolerant](https://en.wikipedia.org/wiki/Byzantine_fault) consensus engine.
+tmsqlite provides an [SQLite](https://www.sqlite.org/)-backed storage layer
+for [Gordian](https://github.com/gordian-engine/gordian)'s
+[tmstore](https://pkg.go.dev/github.com/gordian-engine/gordian/tm/tmstore) package.
 
-A consensus engine is a [replicated state machine](https://en.wikipedia.org/wiki/State_machine_replication) --
-a participant in a distributed system where the participants agree on initial state, actions to apply, and resulting state.
+This module defaults to using [github.com/mattn/go-sqlite3/](https://github.com/mattn/go-sqlite3/)
+for a [CGo](https://pkg.go.dev/cmd/cgo)-backed SQLite driver.
+If CGo is unavailable, it falls back to the [modernc.org/sqlite](https://pkg.go.dev/modernc.org/sqlite) driver,
+which is a pure Go implementation of SQLite.
 
-Gordian allows each participant to have a different voting power.
-This effectively enables Gordian to be the consensus layer in a [proof of stake](https://en.wikipedia.org/wiki/Proof_of_stake) system.
+If CGo is available and you still prefer to run the pure Go driver,
+use the `purego` build tag, e.g. `go test -tags=purego ./...`.
 
-Because Gordian uses an implementation of [the Tendermint® consensus algorithm](https://arxiv.org/abs/1807.04938)[^1],
-systems backed by Gordian can tolerate failure or malicious behavior from participants constituting
-up to, but less than, 1/3 of the total voting power.
+## Project status
 
-## Who should use Gordian?
-
-Gordian was primarily written to support blockchain use cases,
-but it should fit in any distributed system requiring peers to agree on state.
-
-## How do I use Gordian?
-
-Gordian is a modular system written in [Go](https://go.dev/).
-
-The Gordian core Engine is designed to accept messages from the network
-and replay a filtered set of those messages to a state machine.
-The state machine consults a user-provided "driver" to track state changes
-and determine what data to propose to other network participants.
-
-The core Gordian repository (the one you are looking at now) does **not** provide a Driver.
-See [https://github.com/gordian-engine/gcosmos](gcosmos) for an example Driver integrating with the [Cosmos SDK](https://github.com/cosmos/cosmos-sdk).
-
-Outside of the driver, Gordian currently provides a networking layer using [libp2p](https://libp2p.io/),
-a storage layer using [SQLite](https://www.sqlite.org/),
-Ed25519 signing keys for validators,
-and some simple hashing schemes using [BLAKE2b](https://www.blake2.net/).
-
-We have carefully designed the internal APIs to make it as easy as possible to swap out any of those implementations
-(and to test that they comply with expectations within the consensus engine).
-
-While it is easiest to integrate Go code with Gordian,
-it should be straightforward to write a shim layer in Go such that
-you can run an external process and have the core engine communicate with your component.
-There is also the option of [CGo](https://pkg.go.dev/cmd/cgo) if you can provide a C ABI.
-
-Refer to the [`_docs` directory](/_docs) for more technical details.
-
-## Why would I use Gordian?
-
-Most other consensus engines tend to have strong opinions about the way these subsystems work.
-As a result, when teams run into bottlenecks, they are usually stuck looking for small performance gains
-in the underlying framework.
-Gordian makes it easy to swap out parts of the consensus engine,
-whether you are making one small tweak to a standard component or writing one from scratch.
-Whether it's a short experiment or code you've benchmarked and you are taking to production,
-you can relax knowing that you can safely maintain one small library,
-instead of forking the entire consensus engine.
-
-## Try it out
-
-### Full demo with gcosmos
-
-We recommend the earlier mentioned [https://github.com/gordian-engine/gcosmos](gcosmos) repository
-for a full-featured demo involving Gordian integrating with the Cosmos SDK.
-
-### Lightweight demo
-
-Clone the Gordian repository and `cd` into it.
-Make sure you have [the most recent version of Go installed](https://go.dev/dl/).
-Run `./demo-echo.bash start 4` to start a local network of 4 validators,
-running a toy application where the network participants agree on the current height and round.
+tmsqlite passes the [tmstore compliance tests](https://pkg.go.dev/github.com/gordian-engine/gordian/tm/tmstore/tmstoretest)
+and it runs with [gcosmos](https://github.com/gordian-engine/gcosmos),
+but until there is a tagged release, you should assume that the database schema may change in a backwards-incompatible way.
 
 ## License
 
-The Gordian source code is available under the Apache 2.0 license.
+The tmsqlite source code is available under the Apache 2.0 license.
 
 Copyright (c) 2024 Strangelove Crypto, Inc.
-
-[^1]: Tendermint is a registered trademark of All in Bits, Inc.