fix(ralph-loop): restrict semantic completion to DONE promise and assistant entries

- Gate semantic detection on promise === 'DONE' in both transcript and
  session message paths to prevent false positives on VERIFIED promises
- Restrict transcript semantic fallback to assistant/text entries only,
  skipping tool_use/tool_result to avoid matching file content
- Add regression test for VERIFIED promise not triggering semantic detection

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

@@ -273,6 +273,28 @@ describe("detectCompletionInSessionMessages", () => {
       // #then
       expect(detected).toBe(true)
     })
+
+    test("#when promise is VERIFIED #then semantic completion should NOT trigger", async () => {
+      // #given
+      const messages: SessionMessage[] = [
+        {
+          info: { role: "assistant" },
+          parts: [{ type: "text", text: "The task is complete. All work has been finished." }],
+        },
+      ]
+      const ctx = createPluginInput(messages)
+
+      // #when
+      const detected = await detectCompletionInSessionMessages(ctx, {
+        sessionID: "session-123",
+        promise: "VERIFIED",
+        apiTimeoutMs: 1000,
+        directory: "/tmp",
+      })
+
+      // #then
+      expect(detected).toBe(false)
+    })
   })
 })