Depend on tagged Reef v0.1.8

Drops the local replace and the CI step that checked out Reef.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

go.mod

@@ -3,7 +3,7 @@ module git.veillax.com/Veillax/sandbar
 go 1.27.3
 
 require (
-	git.veillax.com/Veillax/reef v0.1.7
+	git.veillax.com/Veillax/reef v0.1.8
 	golang.org/x/crypto v0.58.0
 	modernc.org/sqlite v1.61.0
 )
@@ -19,6 +19,3 @@ require (
 	modernc.org/mathutil v1.7.1 // indirect
 	modernc.org/memory v1.12.1 // indirect
 )
-
-// Local development against an unreleased Reef (it gains secretbox). Remove once Reef is tagged.
-replace git.veillax.com/Veillax/reef => ../reef