docs: state the validation status and correct claims the material contradicts

Assisted-by: DeepSeek V4.1 Flash

cmd/gasm/audit.go

@@ -40,10 +40,13 @@ func cmdAuditInstructions(args []string) error {
 	fs := newCommand("audit-instructions", "gasm audit-instructions [--corpus [dir]] [amd64|arm64|riscv64|loong64]", `
 Compare the gasm encoder for the given architecture (default amd64) against
 go tool asm and print the diff: superset encodings (gasm-only, shippable via
-gasm asm --format goobj), known-but-unencodable names (the backlog) and go-
-only names (feature gaps).  The Go side is probed black-box with a battery
-of bare mnemonics, so the audit tracks whatever toolchain `+"`go env GOROOT`"+`
-provides.
+gasm asm --format goobj) and known-but-unencodable names (the backlog).  The
+Go side is probed black-box one bare mnemonic at a time, so the audit tracks
+whatever toolchain `+"`go env GOROOT`"+` provides; the gasm side answers from
+the encoder table on amd64 and from trial assembly over a battery of operand
+shapes elsewhere.  Names go tool asm knows and gasm does not cannot be
+enumerated by probing, because Go's table is visible only through names
+already in the gasm table; the report closes with a note saying so.
 
 With --corpus the audit changes shape: it assembles every .s file under the
 given directory (default GOROOT/src) with the gasm encoder only, no
@@ -109,7 +112,7 @@ the encodability backlog by frequency rather than by table order.
 
 	w := os.Stdout
 	fmt.Fprintf(w, "gasm table (%s, families excluded): %d mnemonics\n", archName, len(names))
-	fmt.Fprintf(w, "gasm encodable: %d   go tool asm recognized: %d\n", len(shared)+len(superset), countTrue(goKnown))
+	fmt.Fprintf(w, "gasm encodable: %d   go tool asm recognised: %d\n", len(shared)+len(superset), countTrue(goKnown))
 	fmt.Fprintf(w, "shared: %d\n", len(shared))
 	fmt.Fprintf(w, "\nSuperset encodings (gasm-only; ship via gasm asm --format goobj):\n")
 	for _, n := range superset {