v0.9.0

Piano is feature-complete. Every metric -- wall time, self time, CPU time, allocations -- is accurate across sync, threaded, and async execution models.

Added

• Async-aware allocation tracking: allocation data survives thread migrations in async programs, so tokio::spawn and select! no longer silently drop alloc counts (#226, PR #225)

Fixed

• Allocation data no longer silently lost when async tasks migrate threads
• Migrated async guards report real allocations instead of zeros
• Companion JSON merge validates run_id consistency, skipping mismatched files (#58)
• Child exit code propagated from piano profile -- non-zero exits no longer swallowed (#93)
• extern "Rust" fn inside macro_rules! templates now instrumented (#144)
• Stale files removed from staging directory on rebuild
• tempfile moved to dev-dependencies, shrinking the dependency tree for users

Changed

• Staging directory uses a stable path (target/piano/staging/) for incremental compilation instead of a fresh tempdir per build