chore(release): 0.4.1

Bump workspace version 0.4.0 → 0.4.1.

Patch release: dispatch hot-path performance only. No public API
changes; every chart that compiled against 0.4.0 compiles unchanged
and behaves identically. CHANGELOG.md captures the per-pass writeup
under the 0.4.1 heading.

Headlines (deepest dispatch in the bench suite):
  h8_cross_tree     -82% instructions / -72% cycles  vs pre_lca_fix
  bubble_top        -22% instructions /  -6% cycles  vs handler walk
  terminate_event   -22% instructions / -23% cycles  vs PARENT walk

The runtime LCA helper, is_up_transition, the per-call heapless::Vec
ancestry build, the runtime PARENT bubble walk, and (on timer-free
charts) the entire TimerTable machinery are all gone. Callgrind
reports the entire HSM machinery as a single inlined `step` symbol.

Bench suite expanded from 7 to 13 benches: bubble_leaf/mid/top
quantify handler resolution at varying ancestor depths,
timer_fire_dispatch covers the only path that exercises pop_expired's
non-empty branch, terminate_event covers do_terminate, and
bubble_cross_tree covers the realistic HSM worst case (deep bubble +
deep cross-tree transition).

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

CHANGELOG.md

@@ -4,7 +4,7 @@ All notable changes to this workspace are documented here. The format
 follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/) and
 this project adheres to [Semantic Versioning](https://semver.org/).
 
-## Unreleased
+## 0.4.1 — 2026-04-28
 
 ### Performance — dispatch hot path