Generalize UI: general status by default, diagnostics behind Debug details

Rework the spike-era debug readouts into general-purpose status, with the
verbose diagnostics gated behind the menu bar's "Debug details" switch:

- Controllers (was "Phase 0 spike"): always shows slot/source + live
  buttons; the raw stick/trigger numbers are debug-only.
- Injection hook status: general view is attached + focus spoof + a single
  "Game reading controller: N polls/s" summary; the per-slot poll table,
  focus-API counts, and input-path detection are debug-only.
- Audio: general view adds a "Buffered: N ms" health/latency proxy
  (AudioMirror now tracks buffered audio in both render paths) and keeps the
  render-stream count; the per-stream table is debug-only.

Default overlay is now clean general status; flip Debug details for the full
diagnostics. Completes the "generalize the UI" roadmap task. All tests pass.

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

host/src/audio/audio_loopback.cpp

@@ -154,6 +154,7 @@ void AudioMirror::stop()
 	audio_ring_shm_.reset();
 	running_.store(false, std::memory_order_release);
 	source_.store(Source::None, std::memory_order_relaxed);
+	buffered_ms_.store(0, std::memory_order_relaxed);
 	pid_ = 0;
 }
 
@@ -380,6 +381,8 @@ bool AudioMirror::run_hooked(AudioRingHeader* ring)
 			}
 			const UINT32 avail = render_frames - padding;
 			const std::uint32_t ring_bytes = audio_ring_available(*ring);
+			buffered_ms_.store(static_cast<unsigned>(ring_bytes / frame_bytes * 1000 / rate),
+			                   std::memory_order_relaxed);
 			if (!primed && ring_bytes >= prime_bytes)
 			{
 				primed = true;
@@ -571,6 +574,9 @@ void AudioMirror::run_loopback(DWORD pid)
 				continue;
 			}
 			const UINT32 avail = render_frames - padding;
+			buffered_ms_.store(
+			    static_cast<unsigned>(ring.available() / frame_bytes * 1000 / fmt->nSamplesPerSec),
+			    std::memory_order_relaxed);
 			if (!primed && ring.available() >= prime_bytes)
 			{
 				primed = true;

host/src/audio/audio_loopback.hpp

@@ -61,6 +61,13 @@ public:
 		return channels_.load(std::memory_order_relaxed);
 	}
 
+	// Audio currently buffered between capture and the output device, in ms — a
+	// health/latency proxy (rises if the consumer can't keep up). 0 when stopped.
+	[[nodiscard]] unsigned buffered_ms() const
+	{
+		return buffered_ms_.load(std::memory_order_relaxed);
+	}
+
 	// Which capture path is active, for the UI's source indicator.
 	enum class Source
 	{
@@ -107,6 +114,7 @@ private:
 	std::atomic<Source> source_{Source::None};
 	std::atomic<unsigned> sample_rate_{0};
 	std::atomic<unsigned> channels_{0};
+	std::atomic<unsigned> buffered_ms_{0};
 
 	mutable std::mutex status_mutex_;
 	std::string status_;