Fix Ableton Live detection: add root __init__.py and harden Manager init

Live scans the Remote Scripts folder for __init__.py with create_instance()
at the *root* of the script folder. Our create_instance was buried inside
the AbletonOSC/ subpackage, so Live never found it.

Also:
- Inner AbletonOSC/__init__.py: guard import with try/except for pytest compat
- Manager: use show_message() (Live status bar) instead of log_message()
- Manager: wrap OSCServer.start() in try/except OSError so a port conflict
  surfaces as a readable status message instead of a silent crash
- Manager: run handler init inside component_guard() as required by the
  Ableton ControlSurface framework
- Manager stub: add show_message, schedule_message, component_guard no-ops
  so out-of-Ableton tooling/tests don't break

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

AbletonOSC/__init__.py

@@ -1,9 +1,4 @@
-"""
-AbletonOSC — full Ableton Live 11 OSC remote script.
-Ableton calls create_instance() to instantiate the control surface.
-"""
-from .manager import Manager
-
-
-def create_instance(c_instance):
-    return Manager(c_instance)
+try:
+    from .manager import Manager
+except ImportError:
+    pass

AbletonOSC/manager.py

@@ -9,7 +9,8 @@ import sys
 try:
     from ableton.v2.control_surface import ControlSurface
 except ImportError:
-    # Allow importing outside of Ableton for tooling
+    from contextlib import contextmanager
+
     class ControlSurface:  # type: ignore
         def __init__(self, c_instance=None):
             self._c_instance = c_instance
@@ -29,6 +30,16 @@ except ImportError:
         def log_message(self, msg):
             print(msg)
 
+        def show_message(self, msg):
+            print(msg)
+
+        def schedule_message(self, delay, callback):
+            pass
+
+        @contextmanager
+        def component_guard(self):
+            yield
+
 from .osc_server import OSCServer
 from .song import SongHandler
 from .track import TrackHandler
@@ -52,12 +63,17 @@ class Manager(ControlSurface):
     def __init__(self, c_instance=None):
         super().__init__(c_instance)
         self._setup_logging()
-        self.osc_server = OSCServer(listen_port=LISTEN_PORT, send_port=SEND_PORT)
         self._handlers = []
-        self._setup_handlers()
-        self.osc_server.start()
-        logger.info("AbletonOSC started (listen=%d, send=%d)", LISTEN_PORT, SEND_PORT)
-        self.osc_server.send("/live/startup", ())
+        try:
+            self.osc_server = OSCServer(listen_port=LISTEN_PORT, send_port=SEND_PORT)
+            self.osc_server.start()
+            self._setup_handlers()
+            self.show_message("AbletonOSC: Listening on port %d" % LISTEN_PORT)
+            logger.info("AbletonOSC started (listen=%d, send=%d)", LISTEN_PORT, SEND_PORT)
+            self.osc_server.send("/live/startup", ())
+        except OSError as e:
+            self.show_message("AbletonOSC: Couldn't bind to port %d (%s)" % (LISTEN_PORT, e))
+            logger.error("Couldn't bind to port %d: %s", LISTEN_PORT, e)
 
     # ------------------------------------------------------------------
 
@@ -81,10 +97,11 @@ class Manager(ControlSurface):
             BrowserHandler,
             GrooveHandler,
         ]
-        for cls in handler_classes:
-            h = cls(self)
-            h.init_api()
-            self._handlers.append(h)
+        with self.component_guard():
+            for cls in handler_classes:
+                h = cls(self)
+                h.init_api()
+                self._handlers.append(h)
 
         # Control endpoints
         self.osc_server.add_handler("/live/test", self._handle_test)

__init__.py

@@ -0,0 +1,9 @@
+try:
+    from .AbletonOSC.manager import Manager
+except ImportError:
+    # Allows pytest to import without Ableton's runtime present
+    pass
+
+
+def create_instance(c_instance):
+    return Manager(c_instance)

pyproject.toml

@@ -1,6 +1,6 @@
 [build-system]
-requires = ["setuptools>=68"]
-build-backend = "setuptools.backends.legacy:build"
+requires = ["setuptools>=68", "wheel"]
+build-backend = "setuptools.build_meta"
 
 [project]
 name = "ableton-osc"