Initializations: version-addressed init contracts run atomically at publish

[charlesHetterich]

Adds initializations: code that runs exactly once, in the same transaction that publishes a version, against the name's proxy storage. Covers both first-publish setup and upgrade-time storage migration. Closes #77.

How it works

An initialization is addressed by (contract, version) and runs when that version is published. No file for a version → plain publish. A file for an already-published version never runs again.

# Rust                                 # Solidity
counter/                               contracts/
  src/lib.rs                             Counter.sol
  initializations/                       initializations/
    0.1.0.rs                               Counter/
    1.3.0.rs                                 0.1.0.sol

Each file exposes initialize(uint128 from, address owner) — from is the previous latest version (0 on first publish), owner the name's registry owner. A revert rolls back the whole publish.

• Rust: no Cargo.toml changes — cdm deploy builds the file through a generated shim crate. Each file declares its own copy of the contract's storage fields, so old initializations are frozen text that later contract changes can't break.
• Solidity: the file's contract inherits the target (contract Init is Counter); the directory name routes it.

A deploy-time layout guard compares the initialization's storage layout against the implementation's and refuses on mismatch.

On-chain changes

• Per-name proxy gains one admin-only meta op, callCode(address, bytes) — delegatecall into proxy storage, live while frozen (so freeze → publish+init → unfreeze works). The frozen proxy blob is regenerated: 0x9c918a8b…542e86.
• Registry gains publishWithInit(...), which publishes and then calls callCode on the proxy. Initialization contracts are never registered versions, so callCode is the only path to them — no access-control boilerplate needed in user code.

Also

• Templates ship a demonstrative initializations/0.1.0.{rs,sol}; empty constructors removed.
• CI Rust nightly temporarily pinned (Tracking Issue for never type fallback change rust-lang/rust#148922 breaks trie-db).
• e2e: initializations.e2e.test.ts (Rust matrix) + Solidity cases; full local suite green.

[charlesHetterich]

Revised the Solidity convention per review: initializations are now addressed by (contract, version) uniformly — Rust <crate>/initializations/<version>.rs (the crate names the contract), Solidity initializations/<Contract>/<version>.sol (the directory names the contract, mandatory even for single-contract projects). The flat inheritance-routed form collided the moment two contracts needed an initialization at the same version and interleaved per-contract histories; the directory is now the router and inheritance is demoted to validation, with sharp errors for flat-placed files and directories naming no detected contract. PR body updated; foundry template, tests, and docs moved to the nested layout.