feat(audit): list every corpus failure per architecture

docs/man/gasm-audit-instructions.1

@@ -1,8 +1,8 @@
-.TH GASM-AUDIT-INSTRUCTIONS 1 "2026-09-19" "gasm" "User Commands"
+.TH GASM-AUDIT-INSTRUCTIONS 1 "2026-09-21" "gasm" "User Commands"
 .SH NAME
 gasm-audit-instructions \- diff the encoder against the Go toolchain, or measure a corpus
 .SH SYNOPSIS
-.B gasm audit\-instructions [\-\-corpus [\fIdir\fR]] [\-I dir] [amd64|arm64|riscv64|loong64]
+.B gasm audit\-instructions [\-\-corpus [\fIdir\fR]] [\-\-list] [\-I dir] [amd64|arm64|riscv64|loong64]
 .SH DESCRIPTION
 Compare the gasm encoder for the given architecture (default amd64)
 against
@@ -39,6 +39,12 @@ second.
 Assemble a corpus of .s files and report pass rates and failure
 reasons.
 .TP
+.B \-\-list
+With
+.BR \-\-corpus ,
+print every failing file with its failure reason, per architecture,
+instead of one representative file per reason.
+.TP
 .B \-I \fIdir\fR
 Directory to search for #include files; may be repeated, searched in
 order after the source directory.  A corpus run whose files include