🔖 chore: number the legacy-decorator line 0.1.x, not 1.x

Nothing has been published, so a 1.0.0/2.0.0 split claimed a stability and a
history that do not exist. Staying on 0.x says what is true: the API may still
move. Under semver a breaking change is then a minor bump, which is exactly the
relationship between the two lines — 0.1.x keeps legacy experimentalDecorators,
0.2.x moves to TC39 standard decorators.

Branch renamed 1.x -> 0.1.x to match, along with its CI trigger and the
maintenance-line notice in the README.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SAcqrz3FcadkYr3xG32CjK

CHANGELOG.md

@@ -5,12 +5,15 @@ All notable changes to this project are documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [1.0.0] - 2026-08-05
+## [0.1.0] - 2026-08-05
 
-The legacy-decorator line, promoted from 0.1.0 and now maintained in parallel with 2.x.
-Functionally identical to the previous unreleased state; only the version and the
-maintenance-line notice changed. See the 2.x branch for standard decorators and
-compile-time rule checking.
+The legacy-decorator line, now maintained in parallel with 0.2.x. Functionally identical
+to the previous state; only the maintenance-line notice was added. See the 0.2.x branch
+for standard decorators and compile-time rule checking.
+
+The project stays on 0.x while nothing has been published: under semver that signals the
+API may still move, which is honest for software with no real-world users yet. A breaking
+change is therefore a minor bump — 0.1.x to 0.2.x.
 
 
 ### Added