Audio: show echo state honestly for guessed hooked streams

Since guessed streams are now captured-but-not-silenced (the over-write fix),
the hooked path is only no-echo for an exact/override format. The panel
inferred "Hooked (no echo)" unconditionally, which was misleading. Show
"Hooked (echo -- guessed format)" (amber) for a guessed primary stream and
"Hooked (no echo)" (green) only for exact/override; drop the unconditional
"no echo" from source_name() and the mirror status string.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

host/src/audio/audio_loopback.hpp

@@ -86,7 +86,7 @@ public:
 		switch (source())
 		{
 		case Source::Hooked:
-			return "Hooked (no echo)";
+			return "Hooked"; // echo depends on the format provenance; the panel shows it
 		case Source::Loopback:
 			return "Loopback (echo)";
 		default: