🔖 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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "cereale",
-  "version": "1.0.0",
+  "version": "0.1.0",
   "description": "Spring-like decorators for JSON mapping and validation in TypeScript",
   "type": "module",
   "main": "./dist/cjs/index.js",