integrate-revenuecat: end-to-end RevenueCat integration

Use this skill when the user wants to add RevenueCat to a project for the first time, or to reconfigure the SDK with a public API key. The skill covers two halves:

Dashboard side — set up the project, register the app, and obtain the public API key, through the RevenueCat MCP server or the rc CLI.
App side — install the Purchases SDK, call Purchases.configure(…) at app entry, and verify the configuration banner in the logs.

Walk them in order. Most integrations need both halves, even when the user asks "just install the SDK" — the SDK needs an API key from the dashboard.

If a project + app already exist and the user only wants to wire the SDK into code, jump to Section 3 below. If the user wants to bootstrap a brand new RevenueCat project (apps + products + entitlements + offerings), use the create-revenuecat-project skill instead, then come back here for the SDK install.

Arguments

Available as $ARGUMENTS when invoked as a slash command:

platform (optional): One of ios, android, kmp, flutter, react-native. If omitted, run the detection algorithm in Section 3a.
app_identifier (optional): Bundle ID (iOS) or package name (Android). If omitted, read it from the project files (Info.plist, AndroidManifest.xml, app.json, pubspec.yaml).
project_name (optional): Name of the RevenueCat project to use. If omitted, list projects (via MCP or rc projects list) and ask the user.