Codegen Mapping

How Cambrian constructs lower on the public targets.

Solidity-EVM (`--target evm`)

Cambrian	Solidity
`entity E`	Contract `E` (flat file under `src/`)
members	Storage variables (+ transforms inlined into route bodies)
routes	External / public functions
`view` routes	`view` functions
`msg::sender` / `msg::value`	`msg.sender` / `msg.value` (`payable` when value is read)
`~> dest` typed send	External call
`deploy E(...)`	Factory / CREATE2 when deterministic
`event` / `emit`	Solidity `event` / `emit`
`error` / `throw Name`	Custom errors / `revert`
`test` / `property` / `invariant`	Foundry tests / fuzz / invariant handlers

Lean-EVM (`--target lean`)

Cambrian	Lean
entity state	Structure fields (plus ghost key lists for iterated maps when needed)
routes	Functions `World → …` (failing routes in an error monad / `Except`-style surface)
sends / deploys	World updates (`call`, occupancy, balances)
`property` / `test`	Theorems in `*Spec.lean`
`invariant`	`Action` / `step` / `runTrace` style definitions + checks

Prefer reading a generated output tree for the exact file layout; lowering details evolve with each backend.