Rename package directory AbletonOSC/ -> ableton_osc/

Python package naming convention uses snake_case. Update the import in
the root __init__.py and the setuptools include pattern in pyproject.toml.
Internal relative imports within the package are unaffected.

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

ableton_osc/application.py

@@ -0,0 +1,51 @@
+"""Handles /live/application/* OSC addresses."""
+import logging
+from typing import Optional
+from .handler import AbletonOSCHandler
+
+logger = logging.getLogger(__name__)
+
+
+class ApplicationHandler(AbletonOSCHandler):
+    def init_api(self) -> None:
+        self.clear_listeners()
+        self._add("/live/application/get/version", self._get_version)
+        self._add("/live/application/get/average_process_usage",
+                  self._get_average_process_usage)
+        self._add("/live/application/get/peak_process_usage",
+                  self._get_peak_process_usage)
+
+    def _app(self):
+        try:
+            return self.manager.application
+        except Exception:
+            return None
+
+    def _get_version(self, params: tuple) -> Optional[tuple]:
+        app = self._app()
+        if app:
+            try:
+                major, minor = app.get_major_version(), app.get_minor_version()
+                build = app.get_bugfix_version()
+                return (major, minor, build)
+            except Exception as e:
+                logger.warning("get version: %s", e)
+        return None
+
+    def _get_average_process_usage(self, params: tuple) -> Optional[tuple]:
+        app = self._app()
+        if app:
+            try:
+                return (float(app.average_process_usage),)
+            except Exception as e:
+                logger.warning("get avg process usage: %s", e)
+        return None
+
+    def _get_peak_process_usage(self, params: tuple) -> Optional[tuple]:
+        app = self._app()
+        if app:
+            try:
+                return (float(app.peak_process_usage),)
+            except Exception as e:
+                logger.warning("get peak process usage: %s", e)
+        return None