URLPathEscapeAll was only passing [A-Za-z0-9/] through unencoded, causing
it to percent-encode RFC 3986 unreserved characters (-, ., _, ~). Per RFC
3986 §2.3, unreserved characters MUST NOT be percent-encoded, and a URI
that unnecessarily encodes them is not equivalent to one that does not.
Servers that perform strict path matching without normalising
percent-encoded characters will reject the over-encoded form with a 404.
Before: /files/my-report.pdf → /files/my%2Dreport%2Epdf
After: /files/my-report.pdf → /files/my-report.pdf
Reserved characters (spaces, semicolons, colons, etc.) continue to be
encoded as before.
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