chore(Echo): Update tsconfig for declaration generation

Updated the TypeScript configuration in the Echo project to optimize declaration file generation. Added `composite`, `declarationMap`, and `emitDeclarationOnly` flags to enable:
1. Project references for build optimization across Land workspace
2. Source mapping for generated declaration files to improve debugging
3. Exclusive declaration emission since Echo serves as a pure type library

This aligns with Echo's role in the Land architecture as the Tauri IPC contract between Mountain (Rust backend) and Wind (Effect-TS UI services). The changes ensure type safety and developer experience when working with the command/event API, while maintaining separation of concerns in the final synthesized system.

Author: NikolaRHristov

tsconfig.json

@@ -1,10 +1,21 @@
 {
 	"compilerOptions": {
 		"baseUrl": "./",
+
+		"composite": true,
+
+		"declarationMap": true,
+
+		"emitDeclarationOnly": true,
+
 		"lib": ["ESNext"],
+
 		"outDir": "Target",
+
 		"types": ["@cloudflare/workers-types/experimental", "@types/node"]
 	},
+
 	"extends": "@playform/build/tsconfig",
+
 	"include": ["Source"]
 }