fix: add missing API endpoints for volume POST, bypass/toggle, block params, block toggle; fix JACK 1.9.22 cmd args; fix Scarlett 2i2 channel count

src/system/audio.py

@@ -12,6 +12,7 @@ Manages ALSA / JACK / I2S setup on RPi 4B:
 from __future__ import annotations
 
 import logging
+import os
 import re
 import subprocess
 import time
@@ -276,22 +277,28 @@ class AudioSystem:
             return True
 
         profile = self.config.latency_profile
+        jack_env = os.environ.copy()
+        jack_env["JACK_NO_AUDIO_RESERVATION"] = "1"
+        # Scarlett 2i2 needs 2 channels even in mono mode
+        n_in = max(2, self.config.capture_channels)
+        n_out = max(2, self.config.playback_channels)
         cmd = [
             "jackd",
-            f"-P{profile['rt_priority']}",
-            f"-p{profile['period']}",
-            f"-n{profile['nperiods']}",
-            f"-r{profile['rate']}",
-            "-dalsa",
-            f"-d{self.config.output_device}",
-            f"-i{self.config.capture_channels}",
-            f"-o{self.config.playback_channels}",
+            "-P", str(profile['rt_priority']),
+            "-d", "alsa",
+            "-d", self.config.output_device,
+            "-r", str(profile['rate']),
+            "-p", str(profile['period']),
+            "-n", str(profile['nperiods']),
+            "-i", str(n_in),
+            "-o", str(n_out),
         ]
         logger.info("Starting JACK: %s", " ".join(cmd))
 
         try:
             proc = subprocess.Popen(
                 cmd,
+                env=jack_env,
                 stdout=subprocess.DEVNULL,
                 stderr=subprocess.DEVNULL,
             )
@@ -759,14 +766,24 @@ WantedBy=multi-user.target
 
 
 def _jack_is_running() -> bool:
-    """Check if JACK is running via jack_wait."""
+    """Check if JACK is running via process list or PID file."""
     try:
         result = subprocess.run(
-            ["jack_wait", "-c"],
-            capture_output=True, text=True, timeout=5,
+            ["pgrep", "-x", "jackd"],
+            capture_output=True, timeout=3,
         )
         return result.returncode == 0
-    except (FileNotFoundError, subprocess.TimeoutExpired):
+    except FileNotFoundError:
+        # pgrep not available — fall back to pidof
+        try:
+            result = subprocess.run(
+                ["pidof", "jackd"],
+                capture_output=True, timeout=3,
+            )
+            return result.returncode == 0
+        except (FileNotFoundError, subprocess.TimeoutExpired):
+            return False
+    except subprocess.TimeoutExpired:
         return False
 
 
@@ -869,6 +886,9 @@ class JackAudioClient:
         self._active = True
         logger.info("JACK client activated (blocksize=%d)", block_size)
 
+        # Explicitly connect ports to system (JACK auto-connect is unreliable)
+        self._connect_ports()
+
     def stop(self) -> None:
         """Deactivate and close the JACK client."""
         if not self._active or self._client is None:
@@ -889,6 +909,44 @@ class JackAudioClient:
         self._out_buf = None
         logger.info("JACK client stopped")
 
+    # ── Port connection helpers ──────────────────────────────────
+
+    def _connect_ports(self) -> None:
+        """Explicitly connect our ports to the system physical ports.
+
+        JACK's auto-connect is unreliable across systemd service restarts.
+        This ensures audio always flows even when the JACK server was
+        started before our client.
+        """
+        if self._client is None:
+            return
+
+        # Connect each capture port to the corresponding system capture
+        for i, port in enumerate(self._inports):
+            suffix = f"capture_{i + 1}" if self._input_channels > 1 else "capture_1"
+            sys_port_name = f"system:{suffix}"
+            try:
+                sys_ports = self._client.get_ports(sys_port_name)
+                if sys_ports:
+                    self._client.connect(sys_ports[0], port)
+                    logger.debug("Connected %s -> %s", sys_port_name, port.name)
+            except Exception as exc:
+                logger.warning("Failed to connect %s -> %s: %s",
+                               sys_port_name, port.name, exc)
+
+        # Connect each playback port to the corresponding system playback
+        for i, port in enumerate(self._outports):
+            suffix = f"playback_{i + 1}" if self._output_channels > 1 else "playback_1"
+            sys_port_name = f"system:{suffix}"
+            try:
+                sys_ports = self._client.get_ports(sys_port_name)
+                if sys_ports:
+                    self._client.connect(port, sys_ports[0])
+                    logger.debug("Connected %s -> %s", port.name, sys_port_name)
+            except Exception as exc:
+                logger.warning("Failed to connect %s -> %s: %s",
+                               port.name, sys_port_name, exc)
+
     # ── Runtime reconfiguration ────────────────────────────────────
 
     def set_channel_count(self, input_channels: int, output_channels: int) -> None: