✨ Add style tag registry overrides

docs/changes/0.4.0.md

@@ -11,6 +11,8 @@ version 0.4.0
 - feat: add inline style markup support in message text for ANSI text formatter output
 - feat: support named color tags like `<red>...</>`, style tags like `<b>...</>`, and hex tags like `<#ff0000>...</>` / `<bg:#010203>...</>`
 - feat: keep JSON formatter output unchanged and limit inline style parsing to text message rendering only
+- feat: add `TextStyle`, `StyleTagRegistry`, `style_tag_registry()`, and `default_style_tag_registry()` for reusable inline style tags
+- feat: add formatter-local `style_tags`, global style tag registry helpers, builtin-tag override support, and alias reuse via `define_alias(...)`
 
 ### Test
 
@@ -19,6 +21,7 @@ version 0.4.0
 - test: cover config parsing and serialization for `color_mode`
 - test: cover named inline color tags in ANSI mode
 - test: cover plain mode tag stripping, nested tags, hex tags, and unknown-tag fallback behavior
+- test: cover custom tags, builtin-tag override, formatter-vs-global priority, global registry fallback, and alias reuse
 
 ### Example
 
@@ -29,4 +32,4 @@ version 0.4.0
 - `Auto` currently uses a conservative rule: if `NO_COLOR` exists, ANSI is disabled; otherwise ANSI is enabled
 - inline style markup currently supports short close `</>` only
 - unknown or invalid inline tags currently fall back to plain text and do not raise formatter errors
-- tag registry override and configurable style aliases are planned for a later `0.4` batch
+- formatter-local tag lookup currently takes precedence over global tag lookup, and global lookup takes precedence over builtin tags