Normalize three-digit region aliases at the shared locale owner, preserving
caller labels and physical-table reuse. Reject malformed legacy qualifiers
through the same CLI/MCP contract and table classifier.
Adapt the owner correction and regressions from PR #4918 after checking Android
and supported Apktool qualifier sources. Add public MCP validation and preserve
existing two-letter regional selectors.
Fixes#4916
BREAKING CHANGE: Numeric legacy locale selectors such as es-r419 are rejected.
Use es-419 or b+es+419. Two-letter region selectors remain supported.
Co-authored-by: Mert Kaya <[email protected]>