* fix dynamic route vars silently shadow all other vars
* add test
* fix: allow multiple dynamic routes with the same arg
* add test for multiple dynamic args with the same name
* avoid side-effects with DynamicState tests
* fix dynamic route integration test which shadowed a var
* fix darglint
* refactor to DynamicRouteVar
* old typing stuff again
* from typing_extensions import Self
try to keep typing backward compatible with older releases we support
* Raise a specific exception when encountering dynamic route arg shadowing
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Co-authored-by: Masen Furer <m_github@0x26.net>