fix(container): copy crates/ into minimal Containerfile build context

The root `echidna` package is a Cargo workspace whose members include
crates/{echidna-core,echidna-core-spark,echidna-mcp,echidna-wire,typed_wasm}.
Stage-1 only COPYed Cargo manifests + src/rust + src/interfaces, so
`cargo build --release --bin echidna` failed reading
/build/crates/echidna-core/Cargo.toml (No such file or directory).
Pre-existing breakage (container-ci.yml has been red on main); surfaced
by #73's container-ci touch. Adds `COPY crates ./crates`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

Containerfile

@@ -26,6 +26,12 @@ WORKDIR /build
 COPY Cargo.toml Cargo.lock ./
 COPY src/rust ./src/rust
 COPY src/interfaces ./src/interfaces
+# The root `echidna` package is a Cargo workspace whose members include
+# crates/* (echidna-core, -core-spark, -mcp, -wire, typed_wasm). Cargo
+# loads every member manifest when building the bin, so the crates/ tree
+# must be in the build context too — omitting it fails the build with
+# `failed to read /build/crates/echidna-core/Cargo.toml`.
+COPY crates ./crates
 
 RUN cargo build --release --bin echidna