chore(Common): Update TypeScript config for declaration emission

Modified the `tsconfig.json` in the `Common` element to optimize TypeScript declaration file generation for shared DTOs and interfaces. Key changes:

1. Added `composite: true` to enable project references, allowing other Land components (`Cocoon`, `Wind`) to build against `Common`'s type definitions
2. Enabled `declarationMap: true` to provide source mapping for generated `.d.ts` files, improving developer experience when navigating shared types
3. Set `emitDeclarationOnly: true` since `Common` contains only type definitions (abstract traits and DTOs) without runtime JS code
4. Specified `rootDir: '.'` to ensure declaration files maintain correct relative paths

This aligns with Land's architecture where `Common` serves as the central type library defining gRPC contracts and effect interfaces used across Rust (`Mountain`) and TypeScript (`Cocoon`/`Wind`) components. The changes ensure type safety during cross-component development while eliminating unnecessary JS output for this pure-type crate.

Author: NikolaRHristov

tsconfig.json

@@ -2,10 +2,18 @@
 	"compilerOptions": {
 		"baseUrl": "./",
 
+		"composite": true,
+
+		"declarationMap": true,
+
+		"emitDeclarationOnly": true,
+
 		"lib": ["ESNext"],
 
 		"outDir": "Target",
 
+		"rootDir": ".",
+
 		"types": ["@cloudflare/workers-types/experimental", "@types/node"]
 	},