fix(ralph-loop): detect promise tags in tool_result parts for ulw verification

Oracle's <promise>VERIFIED</promise> arrives as a tool_result part from the
task() tool call, not as a text part. Both detectCompletionInSessionMessages
and collectAssistantText only scanned type=text parts, missing the
verification signal entirely. This caused ulw loops to fail verification
even when Oracle successfully emitted VERIFIED.

Include tool_result parts in promise detection alongside text parts.
Exclude tool_use parts to avoid false positives from instructional text.

src/hooks/ralph-loop/completion-promise-detector.ts

@@ -93,7 +93,7 @@ export async function detectCompletionInSessionMessages(
 
 			let responseText = ""
 			for (const part of assistant.parts) {
-				if (part.type !== "text") continue
+				if (part.type !== "text" && part.type !== "tool_result") continue
 				responseText += `${responseText ? "\n" : ""}${part.text ?? ""}`
 			}