BWF Analyser: browser page and macOS app

Reads and edits BWF metadata for production sound. One source tree builds a
single self-contained page and a native Tauri app with a Rust audio engine and
WAV writer. Around 370 checks across seven test suites.

First commit of the existing state, so that from here every change can be
seen and undone.

mac-app/src-tauri/capabilities/default.json

@@ -0,0 +1,13 @@
+{
+  "identifier": "default",
+  "description": "Core APIs plus the native open dialog. The app's own bwf_* commands are not listed here: commands defined by the application itself, called from its own local frontend, are allowed without an ACL entry. Only plugin commands need one.",
+  "windows": [
+    "main"
+  ],
+  "permissions": [
+    "core:default",
+    "dialog:allow-open",
+    "dialog:allow-save",
+    "window-state:default"
+  ]
+}