fix(libmoq): update tests for moq_origin_publish handle return

[kixelated]

Summary

cargo test -p libmoq --all-features was crashing with a SIGSEGV (signal 11) and a non-unwinding panic. The failing tests (local_announce, catalog_update_on_new_track, announced_deactivation, consume_announced_local, double_close_all_resource_types, and others) all panicked first on an assertion like assert_eq!(moq_origin_publish(...), 0).

Root cause: stale tests, not a callback bug. #1640 changed moq_origin_publish to return a positive publish handle (paired with the new moq_origin_unpublish) under the RAII OriginPublish model, but never updated rs/libmoq/src/test.rs, which still asserted a 0 return. This went unnoticed because CI's cargo check --workspace --all-features failed to compile (NVENC) since #1691, so cargo test --all-features never actually ran until the moq-video CI plumbing was fixed in #1704.

Why it segfaulted. The failed == 0 assertion panicked each test mid-flight, which dropped the test's Callback (freeing user_data) without draining the terminal callback via recv_terminal(). The still-alive background announce/catalog task then fired its callback into freed memory: a use-after-free → SIGSEGV. The terminal-callback contract in the production code (free user_data exactly once, in the final callback) was already correct (#1546) and is unchanged.

Changes (test-only)

• Capture the publish handle with id() (which still asserts it is positive) at all 10 call sites, instead of asserting == 0.
• announced_deactivation previously deactivated by closing the broadcast producer. Under the OriginPublish model, dropping the producer no longer unannounces, so it now deactivates via moq_origin_unpublish(publish) and closes the broadcast at the end.

Test plan

• cargo test -p libmoq --all-features — 23 passed, 0 failed, no abort (run 3×, repeatable)
• cargo test -p libmoq (default features) — 23 passed
• cargo fmt -p libmoq --check — clean
• cargo clippy -p libmoq --all-features — clean

No public API or wire behavior changes (test-only). Targets dev, since the moq_origin_publish handle change (#1640) and the CI fix that surfaced this (#1704) both live there.

(Written by Claude)