Change getAllTools() to return ToolInfo[] instead of string[]

Breaking change: pi.getAllTools() now returns Array<{ name, description }>
instead of string[]. Extensions needing just names can use .map(t => t.name).

Removes redundant getToolInfo() method added in original PR.

Fixes #647

packages/coding-agent/src/core/extensions/loader.ts

@@ -187,7 +187,7 @@ function createExtensionAPI(
 			return runtime.getActiveTools();
 		},
 
-		getAllTools(): string[] {
+		getAllTools() {
 			return runtime.getAllTools();
 		},