fix: all dummy data replaced with real API data

- Status bar: CPU load + sample rate from /api/state, TUNER badge shown immediately
- Rig: optimistic toggle updates (bypass/tuner respond instantly), prominent tuner card
- FX Chain: loads real block params from /api/block-params/{fx_type}, Add Block picker with all FX types
- Record: replaced fake multitrack with real Signal Monitor (live I/O VU, clip detect, level history)
- Backend: added _gather_system_stats() returning cpu_percent and sample_rate

src/web/server.py

@@ -29,7 +29,7 @@ from fastapi.templating import Jinja2Templates
 
 from ..dsp.nam_host import NAMHost
 from ..dsp.ir_loader import IRLoader
-from ..dsp.pipeline import AudioPipeline
+from ..dsp.pipeline import AudioPipeline, SAMPLE_RATE
 from ..presets.manager import PresetManager
 from ..presets.types import FXBlock, FXType, Preset
 from ..system.tonedownload import (
@@ -1001,6 +1001,19 @@ class WebServer:
                     "address": None, "discoverable": False,
                     "midi_enabled": False, "midi_running": False}
 
+    # ── System state gathering ────────────────────────────────────
+
+    def _gather_system_stats(self) -> dict:
+        """Gather system stats (CPU, audio config) without hard-failing."""
+        try:
+            import psutil
+            return {
+                "cpu_percent": psutil.cpu_percent(interval=None),
+                "sample_rate": SAMPLE_RATE if hasattr(self, 'deps') and self.deps.pipeline else 48000,
+            }
+        except Exception:
+            return {"cpu_percent": 0, "sample_rate": 48000}
+
     # ── State gathering ──────────────────────────────────────────────
 
     def _gather_state(self) -> dict[str, Any]:
@@ -1025,6 +1038,8 @@ class WebServer:
                 "ir_name": None,
                 "input_level": 0,
                 "output_level": 0,
+                "cpu_percent": 0,
+                "sample_rate": 48000,
                 "wifi": {},
                 "bluetooth": {},
             }
@@ -1070,6 +1085,9 @@ class WebServer:
             # Audio levels from pipeline (RMS float32 normalized 0.0-1.0, scaled to 0-100)
             "input_level": min(100, round((pl._input_level or 0.0) * 150)) if pl else 0,
             "output_level": min(100, round((pl._output_level or 0.0) * 150)) if pl else 0,
+            # System stats
+            "cpu_percent": self._gather_system_stats().get("cpu_percent", 0),
+            "sample_rate": SAMPLE_RATE,
             "wifi": self._gather_wifi_state(),
             "bluetooth": self._gather_bt_state(),
         }