refactor: rename crate fai-module-sdk -> chain-module-sdk

The SDK is product-scoped (Ch∆In's module SDK), not a generic vendor
crate — a future Brain SDK would collide. Crate + macros renamed to
chain-module-sdk[-macros]; repo + dir follow.

Signed-off-by: flemming-it <sf@flemming.it>

crates/fai-module-sdk/tests/wit_freeze.rs

@@ -1,53 +0,0 @@
-//! Snapshot test for the WIT mirror.
-//!
-//! The SDK ships its own copy of `wit/world.wit` so the proc-macro
-//! can embed it via `include_str!` at compile time. The hash MUST
-//! match the platform's frozen v1.0 hash. If this test fails, the
-//! mirror has drifted and the SDK cannot guarantee binary
-//! compatibility with the platform.
-
-#![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]
-
-use std::path::PathBuf;
-
-use sha2::{Digest, Sha256};
-
-/// Identical to FROZEN_WIT_SHA256 in
-/// fai/platform :: crates/fai_runtime/tests/wit_freeze.rs.
-/// Update both repos in lockstep, never one alone.
-const PLATFORM_FROZEN_WIT_SHA256: &str =
-    "6f4e2266a4264832a16fe5a3704622cd978b290b90f3300c3ed236d98b689b5f";
-
-fn world_wit_path() -> PathBuf {
-    PathBuf::from(env!("CARGO_MANIFEST_DIR"))
-        .parent()
-        .expect("crates parent")
-        .parent()
-        .expect("workspace root")
-        .join("wit")
-        .join("world.wit")
-}
-
-#[test]
-fn wit_mirror_matches_platform_frozen_hash() {
-    let path = world_wit_path();
-    let bytes = std::fs::read(&path).unwrap_or_else(|e| panic!("read {}: {e}", path.display()));
-
-    let mut hasher = Sha256::new();
-    hasher.update(&bytes);
-    let actual = format!("{:x}", hasher.finalize());
-
-    assert_eq!(
-        actual, PLATFORM_FROZEN_WIT_SHA256,
-        "\n\nwit/world.wit in this repo has drifted from the platform's\n\
-         frozen v1.0 hash. The SDK MUST mirror the platform exactly\n\
-         or modules built with this SDK will not be wire-compatible.\n\n\
-         If the platform intentionally bumped to a new minor (e.g.\n\
-         v1.1 with additive changes), update BOTH:\n\
-           1. wit/world.wit here to match the platform copy\n\
-           2. PLATFORM_FROZEN_WIT_SHA256 in this test\n\n\
-         If the platform is still on the old hash, revert this WIT\n\
-         change.\n\n\
-         actual hash: {actual}\n"
-    );
-}