fix: two fatal errors preventing plugin activation (v0.1.1)

1. NAMESPACE is a PHP reserved keyword — renamed to REST_NAMESPACE
   in the REST controller. This caused a parse error on activation.

2. Autoloader can't resolve PR_Core class — the class name equals the
   autoloader prefix exactly, so stripping "PR_Core_" yields an empty
   suffix and the wrong filename. Added explicit require_once in
   bootstrap, same pattern as PRAutoBlogger.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -3,6 +3,15 @@
 All notable changes to Peptide Repo Core are documented here.
 Format: [Semantic Versioning](https://semver.org/).
 
+## [0.1.1] — 2026-04-19
+
+### Fixed
+- **Fatal error on activation: `NAMESPACE` is a PHP reserved keyword.** Renamed
+  to `REST_NAMESPACE` in the REST controller.
+- **Fatal error: autoloader cannot resolve `PR_Core` class.** Class name equals
+  the autoloader prefix exactly, producing wrong filename. Added explicit
+  require_once in bootstrap (same pattern as PRAutoBlogger).
+
 ## [0.1.0] — 2026-04-17
 
 ### Added