refactor(launcher): canonicalize default profiles

documentation/PROJECT__AE_Events_Launcher_Native_integration.md

@@ -41,7 +41,8 @@ The integration is built on a decoupled three-layer communication model to ensur
 - **Role:** Provides a clean, typed API for Svelte components.
 - **Responsibilities:**
   - Mapping `camelCase` UI triggers to `snake_case` IPC calls.
-  - Resolving a Launch Profile to a single `native_template` string before crossing IPC.
+  - Resolving an extension alias to a canonical Launch Profile, then to a single
+    `native_template` string before crossing IPC.
 
 The reason for this split is simple: Launch Profiles are policy, while Native Templates are
 executable strings. Keeping that distinction explicit prevents the bridge from mixing config
@@ -199,6 +200,11 @@ resolved a template yet, it should stop before IPC and surface a missing-profile
 This keeps all fallback logic in Svelte, where it can be edited without rebuilding Electron.
 The native layer should not invent or guess a default launch path.
 
+The built-in defaults are organized as canonical profile names plus extension aliases. That
+lets multiple file types share one profile without repeating the same app/script details.
+URL-based presentations remain a special pseudo-extension handled separately from the cache
+open flow.
+
 ### Native Template Formats
 
 | Format | Example |