The MT stream initializer previously exposed one C callback that waited for
all submitted jobs and then released their resources. That left the ordering
policy in C even though Rust already owned the surrounding initialization
sequence and the ring-order wait/release policies.
Expose separate wait-all and release-all callbacks at the Rust/C boundary and
invoke them in Rust in the original wait-before-release order. C retains the
worker synchronization, job descriptors, input buffer, and resource-pool
side effects behind the two callbacks, while the focused Rust initializer test
now makes the ordering explicit.
Test Plan:
- capped cargo +nightly fmt for the Rust workspace -- passed
- capped root cargo clippy --all-targets -- -D warnings -- passed
- capped serial make -j1 for the single-threaded library, MT library, and CLI -- passed
- git diff --cached --check -- passed