fix: improve session recovery and audio recorder reliability

frontend/src/contexts/InterviewContext.jsx

@@ -134,6 +134,25 @@ export function InterviewProvider({ children }) {
                 sessionId: sid
               }
             });
+          } else if (storedStep === "interview" && status.status === "active") {
+            // Last answer was already saved, but no unanswered question is active.
+            // This happens after a refresh between scoring and fetching the next question.
+            const next = await api.nextQuestion(sid);
+            if (next.status === "completed" || next.status === "awaiting_wrapup_answer" || !next.question) {
+              dispatch({ type: "CLEAR_QUESTION" });
+              dispatch({ type: "SET_STEP", v: "processing" });
+            } else {
+              dispatch({
+                type: "RESTORE_STATE",
+                state: {
+                  step: "interview",
+                  question: next.question,
+                  questionNumber: (status.questions_asked_count || 0) + 1,
+                  totalQuestions: next.total_questions || status.total_questions,
+                  sessionId: sid
+                }
+              });
+            }
           }
           // If no active question, user stays at their current step
         } catch (e) {
@@ -158,8 +177,13 @@ export function InterviewProvider({ children }) {
     try {
       await api.startInterview(state.sessionId);
       const res = await api.nextQuestion(state.sessionId);
-      dispatch({ type: "SET_QUESTION", v: res.question, total: res.total_questions || 0 });
-      setStep("interview");
+      if (res.status === "completed" || res.status === "awaiting_wrapup_answer" || !res.question) {
+        setLoading(false);
+        setStep("processing");
+      } else {
+        dispatch({ type: "SET_QUESTION", v: res.question, total: res.total_questions || 0 });
+        setStep("interview");
+      }
     } catch (e) {
       setError(e.message || "Could not start interview.");
     }
@@ -226,7 +250,7 @@ export function InterviewProvider({ children }) {
     try {
       // Use formal skip endpoint that properly updates backend state
       const result = await api.skipQuestion(state.sessionId, state.question.id);
-      if (!result.next_question || result.next_question?.status === "completed") {
+      if (!result.next_question) {
         setStep("processing");
         return;
       }

frontend/src/hooks/useAudioRecorder.js

@@ -24,10 +24,19 @@ export function useAudioRecorder() {
   
   const mediaRef  = useRef(null);
   const chunksRef = useRef([]);
+  const audioURLRef = useRef(null);
+  const suppressStopBlobRef = useRef(false);
   const audioCtxRef = useRef(null);
   const analyserRef = useRef(null);
   const rafRef = useRef(null);
 
+  const revokeAudioURL = useCallback(() => {
+    if (audioURLRef.current) {
+      URL.revokeObjectURL(audioURLRef.current);
+      audioURLRef.current = null;
+    }
+  }, []);
+
   const updateVolume = useCallback(() => {
     if (!analyserRef.current) return;
     const dataArray = new Uint8Array(analyserRef.current.frequencyBinCount);
@@ -50,7 +59,8 @@ export function useAudioRecorder() {
   const start = useCallback(async () => {
     setMicError(null);
     
-    if (audioURL) URL.revokeObjectURL(audioURL);
+    suppressStopBlobRef.current = false;
+    revokeAudioURL();
     setAudioBlob(null);
     setAudioURL(null);
     setVolume(0);
@@ -82,6 +92,9 @@ export function useAudioRecorder() {
         // Small delay to ensure all dataavailable events have fired
         setTimeout(() => {
         try {
+          if (suppressStopBlobRef.current) {
+            return;
+          }
           if (chunksRef.current.length === 0) {
             console.warn("No audio chunks collected.");
             setMicError("No audio was captured. Please speak into the microphone.");
@@ -91,6 +104,7 @@ export function useAudioRecorder() {
 
           const blob = new Blob(chunksRef.current, { type: mimeType || "audio/webm" });
           const newURL = URL.createObjectURL(blob);
+          audioURLRef.current = newURL;
           setAudioBlob(blob);
           setAudioURL(newURL);
         } catch (err) {
@@ -118,7 +132,7 @@ export function useAudioRecorder() {
       console.error("Mic access failed:", e);
       setMicError("Microphone access denied. Please allow microphone access and try again.");
     }
-  }, [audioURL]);
+  }, [revokeAudioURL]);
 
   useEffect(() => {
     if (recording) {
@@ -142,9 +156,10 @@ export function useAudioRecorder() {
   const reset = useCallback(() => {
     // Stop any active recording first
     if (mediaRef.current && mediaRef.current.state !== "inactive") {
+      suppressStopBlobRef.current = true;
       mediaRef.current.stop();
     }
-    if (audioURL) URL.revokeObjectURL(audioURL);
+    revokeAudioURL();
     setAudioBlob(null);
     setAudioURL(null);
     setRecording(false);
@@ -152,13 +167,13 @@ export function useAudioRecorder() {
     setVolume(0);
     chunksRef.current = [];
     mediaRef.current = null;
-  }, [audioURL]);
+  }, [revokeAudioURL]);
 
   useEffect(() => {
     return () => {
-      if (audioURL) URL.revokeObjectURL(audioURL);
+      revokeAudioURL();
     };
-  }, [audioURL]);
+  }, [revokeAudioURL]);
 
   return { 
     recording,