Split deploy half out of rainlang (rainix#296) #552

Part of the org-wide repo refactor tracked in rainlanguage/rainix#296.

What

Split this repo into a library half (stays here, autopublishes to Soldeer on merge via rainix-autopublish) and a deploy half (new rainlang.deploy repo, releases only on a manual sol-v* tag via rainix-tag-release). Every repo must end up strictly one or the other, never both.

Why this repo

Carries both halves at scale: 9 deploy artifacts and 7 concrete contracts — Rainlang, RainlangExpressionDeployer, RainlangInterpreter, RainlangParser, RainlangStore and RainlangReferenceExtern. That is seven deploy suites against rain.factory's one.

Its release lane is wedged: [package].version is 0.1.8 and the published rainlang revision is also 0.1.8, so rainix-autopublish's next-version invariant rejects every run. It has been failing since 2026-07-16.

This is currently blocking other work. Six repos could not complete the rain-math-binary 0.1.1 → 0.1.3 bump on 2026-08-13 because rainlang's published source imports rain-math-binary-0.1.1/src/lib/LibCtPop.sol and it cannot republish.

Two complications rain.factory did not have

1. src/generated/ is flat, not the frozen per-tag src/generated/<tag>/ layout. The split includes migrating to the snapshot model, not just relocating files.
2. Five Rust crates publish to crates.io in the same release lane — rainlang_bindings, rainlang_dispair, rainlang_parser, rainlang-eval, rainlang_test_fixtures — as a lockstep set. Reconciling a crates.io cadence against a deploy tag is new ground.

Because of both, this should follow the smaller proofs (rain.extrospection, rain.tofu.erc20-decimals, rain.pyth, rain.flare, rain.metadata, rain.math.float) rather than lead them.

Method

Follow rainlanguage/rain.factory#46: verify the cut is one-way first, then create the .deploy repo with the concrete contracts, deploy-pin lib, frozen snapshots and deploy scripts under rainix-tag-release; release it; slim this repo; migrate consumers.

Soldeer revisions are immutable and this org carries the version inside the import path, so existing consumers stay pinned to working revisions throughout.

Done when

• Cut verified one-way
• src/generated/ migrated to the frozen per-tag layout
• Rust crate release cadence reconciled with the deploy tag
• rainlang.deploy created with the deploy half
• rainlang.deploy released, pins published
• This repo slimmed to the library half
• Release lane publishes cleanly
• The blocked rain-math-binary 0.1.3 bumps can proceed