TASK-049-003: Update all using directives from RFC9112 to Http11

All consumer files now import `TurboHttp.Protocol.Http11` instead of the
deprecated `TurboHttp.Protocol.RFC9112` namespace. No logic changes — only
`using` directive updates. This was completed as part of TASK-049-002 (the
namespace rename) so no additional file edits were required in this task.

Author: st0o0

.maggus/features/feature_049.md .maggus/features/feature_049_completed.md.maggus/features/feature_049.md renamed to .maggus/features/feature_049_completed.md

@@ -96,8 +96,8 @@ and their namespace declarations updated.
 **Parallel:** no
 
 **Acceptance Criteria:**
-- [ ] No `using TurboHttp.Protocol.RFC9112;` anywhere in the solution
-- [ ] All identified consumer files import `TurboHttp.Protocol.Http11`
-- [ ] No logic changes — only `using` directive updates
+- [x] No `using TurboHttp.Protocol.RFC9112;` anywhere in the solution
+- [x] All identified consumer files import `TurboHttp.Protocol.Http11`
+- [x] No logic changes — only `using` directive updates
 
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