Model command alias prefix rewriting

docs/roadmap/implementation.md

@@ -291,6 +291,12 @@ count; target expansion; group suffix preservation; shorter fallback after
 a failed longer token match; unknown tokens; empty suffixes. The compiler
 and direct resolver agree on these terminating cases.
 
+**Completed:** Added the independent longest-prefix resolver and compiled its
+trie into a finite stack machine with literal and `OTHER` symbols, end and
+flag-boundary markers, shorter-match fallback, restoration, and normalized
+pushes. A test-only interpreter matches direct resolution for the recorded
+finite cases. Verified with `go test ./internal/alias`.
+
 ## Stage 3: Prove and test termination validation
 
 **Work**