Reset version to 1.0.0 and add TODO/CHANGELOG

Reset all Path A script versions from 3.x to 1.0.0 following architectural
decision to treat this as a fresh stable baseline after the Path B cleanup.
Added TODO.md with prioritized audit findings and replaced the old CHANGELOG
with a clean stub.

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

lib/validation.sh

@@ -2,7 +2,7 @@
 
 # HOPS - Input Validation and Sanitization Functions
 # Comprehensive input validation and sanitization utilities
-# Version: 3.1.0-beta
+# Version: 1.0.0
 
 # Source common functions
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"