Use mcdsl/terminal for all password prompts

Replace direct golang.org/x/term calls with mcdsl/terminal.ReadPassword
across mciasctl (6 sites), mciasgrpcctl (1 site), and mciasdb (1 site).
Aligns with the new CLI security standard in engineering-standards.md.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

vendor/modernc.org/libc/libc_freebsd.go

@@ -2480,3 +2480,24 @@ func Xdup(tls *TLS, fd int32) (r int32) {
 
 	return int32(nfd)
 }
+
+func X__inline_isnand(t *TLS, x float64) int32 {
+	if __ccgo_strace {
+		trc("t=%v x=%v, (%v:)", t, x, origin(2))
+	}
+	return Xisnan(t, x)
+}
+
+func X__inline_isnanf(t *TLS, x float32) int32 {
+	if __ccgo_strace {
+		trc("t=%v x=%v, (%v:)", t, x, origin(2))
+	}
+	return Xisnanf(t, x)
+}
+
+func X__inline_isnanl(t *TLS, x float64) int32 {
+	if __ccgo_strace {
+		trc("t=%v x=%v, (%v:)", t, x, origin(2))
+	}
+	return Xisnan(t, x)
+}