fix: upgrade example to RN 0.76 and simplify to legacy bridge

- Upgrade example app from RN 0.73 to 0.76 to fix Node.js 23 babel
  compatibility issue (addHelper error)
- Remove TurboModule cpp files - using legacy bridge for now
- Simplify podspec to legacy bridge architecture only
- Add complete iOS project structure for example app
- Fix AppDelegate to use bundleURL method (RN 0.76 requirement)
- Simplify NativeFluidAudio.ts spec to use Object types for codegen

Author: Alex-Wengg

cpp/FluidAudioModule.h

@@ -0,0 +1,11 @@
+# This `.xcode.env` file is versioned and is used to source the environment
+# used when running script phases inside Xcode.
+# To customize your local environment, you can create an `.xcode.env.local`
+# file that is not versioned.
+
+# NODE_BINARY variable contains the PATH to the node executable.
+#
+# Customize the NODE_BINARY variable here.
+# For example, to use nvm with brew, add the following line
+# . "$(brew --prefix nvm)/nvm.sh" --no-use
+export NODE_BINARY=$(command -v node)

cpp/FluidAudioTurboModule.cpp

@@ -0,0 +1,2 @@
+export NODE_BINARY=/opt/homebrew/bin/node
+