Ship the 0.9.0 production-quality milestone

Add mixer/accessibility settings, caption/reduce-motion hooks, audio volume
clamping, a 24-NPC performance smoke and shortened coat/dress stride for hem
clipping. Record the explicit Godot 4.3-CI/4.7-local matrix and the 0.9
production scope. Headless 250/250, Python 94/94, 24-NPC budget smoke passes.

CHANGELOG.md

@@ -4,6 +4,27 @@ All notable user-facing changes to Gig Line. The format follows
 [Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and versions use
 Semantic Versioning.
 
+## [0.9.0] — 2026-11-01
+
+### Added
+
+- Master/SFX/ambience volume controls, a captions toggle and a Reduce motion
+  option in Settings.
+- A 24-NPC performance budget smoke and expanded audio/accessibility coverage.
+- Explicit production-quality scope for animation, audio, localization and the
+  Godot 4.3-CI/4.7-local support matrix.
+
+### Changed
+
+- Coat and dress strides are shortened to reduce hem/leg clipping.
+- Help and the shift-review surface expose the current policy and accessibility
+  settings.
+
+### Fixed
+
+- Audio cue volumes now respect the player's mixer settings while remaining
+  headless-safe.
+
 ## [0.8.1] — 2026-11-01
 
 ### Fixed