chore: version bump to rc 12 (#125)

Author: Fraser999

.gitignore

@@ -1,2 +1,4 @@
 /target
 Cargo.lock
+.claude/*.local.*
+CLAUDE.local.md

Cargo.toml

@@ -3,7 +3,7 @@ name = "init4-bin-base"
 
 description = "Internal utilities for binaries produced by the init4 team"
 keywords = ["init4", "bin", "base"]
-version = "0.18.0-rc.11"
+version = "0.18.0-rc.12"
 edition = "2021"
 rust-version = "1.85"
 authors = ["init4", "James Prestwich", "evalir"]