1.2 FrameName value type

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

IMPLEMENTATION.md

@@ -41,7 +41,7 @@ Each type lives in `src/FrameProcessor/Domain/`. Tests in `tests/FrameProcessor.
 - ASP.NET route value binding (e.g., `IParsable<MacAddress>`).
 - **Tests:** `MacAddressTests` covering round-trip from all four input forms, equality on bytes, rejection of bad input.
 
-### [ ] 1.2 `FrameName`
+### [x] 1.2 `FrameName`
 - `record struct` wrapping a validated string.
 - Constructor / `TryParse` enforces RFC 3986 unreserved (`A-Z a-z 0-9 - . _ ~`), non-empty.
 - JSON converter + `IParsable`.