Persist discovery answers to CSV for reprocessing and recovery

Save each discovery conversation's prompts and answers to durable CSV
files (per-conversation + append-only master log) on both save and
completion, so answers survive an extraction error, can be re-fed to the
AI, and can be reviewed/resumed by the user.

- app/services/answer_store.py: canonical prompt list + atomic CSV writes,
  master append, and read-back helpers (DB stays system of record; CSV
  failures are logged, never fatal).
- discovery router: write CSV on /respond and /complete; new endpoints
  GET /answers, GET /answers.csv, POST /reprocess (shared extraction
  helper; locked profiles return 409).
- discovery.html: prefill/resume from saved answers after an error and a
  "Re-run analysis" button wired to /reprocess.
- scripts/reprocess_csv.py: offline CLI to re-run extraction from a CSV
  (print or --write-db).
- QUESTIONS_DIR / QUESTIONS_MASTER_CSV config, .gitignore, README, tests.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Dg6XWUwprmP5QCL18HxssY

app/static/discovery.html

@@ -133,11 +133,62 @@
       }
     });
 
+    const STORAGE_KEY = "discovery_conversation_id";
+
     async function startConversation() {
       const res = await authedFetch("/discovery/start", { method: "POST" });
       if (!res.ok) throw new Error("Could not start conversation");
       const data = await res.json();
       conversationId = data.conversation_id;
+      // Remember the in-progress conversation so a reload after an error can
+      // resume from the original answers rather than losing them.
+      try {
+        localStorage.setItem(STORAGE_KEY, conversationId);
+      } catch (e) {
+        /* storage unavailable — non-fatal */
+      }
+    }
+
+    async function resumeOrStart() {
+      let savedId = null;
+      try {
+        savedId = localStorage.getItem(STORAGE_KEY);
+      } catch (e) {
+        /* storage unavailable */
+      }
+      if (savedId) {
+        try {
+          const res = await authedFetch(`/discovery/${savedId}/answers`);
+          if (res.ok) {
+            const data = await res.json();
+            const hasText = (data.answers || []).some((a) => a.answer.trim());
+            if (!data.completed_at && hasText) {
+              // Resume: restore the saved answers into the flow.
+              conversationId = savedId;
+              const byKey = {};
+              data.answers.forEach((a) => {
+                byKey[a.prompt_key] = a.answer;
+              });
+              PROMPTS.forEach((p, i) => {
+                // CSV/key uses the short key; PROMPTS uses prompt_* column names.
+                const shortKey = p.key.replace(/^prompt_/, "");
+                answers[i] = byKey[shortKey] || "";
+              });
+              render();
+              return;
+            }
+          }
+        } catch (e) {
+          /* fall through to a fresh start */
+        }
+      }
+      // No resumable conversation — start a fresh one.
+      try {
+        localStorage.removeItem(STORAGE_KEY);
+      } catch (e) {
+        /* ignore */
+      }
+      await startConversation();
     }
 
     async function submit() {
@@ -173,24 +224,70 @@
           throw new Error(detail.detail || "Extraction failed");
         }
 
+        // Success: the conversation is complete, drop the resume marker.
+        try {
+          localStorage.removeItem(STORAGE_KEY);
+        } catch (e) {
+          /* ignore */
+        }
         window.location.href = "/static/profile.html";
       } catch (err) {
         el.loading.classList.remove("active");
         el.flow.style.display = "block";
         el.flow.innerHTML =
           `<div class="error-box"><strong>Something went wrong.</strong><br/>` +
-          `${err.message}<br/><br/>Your answers are still here — ` +
-          `please try submitting again.</div>` +
+          `${err.message}<br/><br/>Your answers are saved — you can ` +
+          `re-run the analysis or reload to keep editing.</div>` +
+          `<div class="nav">` +
+          `<button class="btn-ghost" onclick="location.reload()">Reload</button>` +
+          `<button class="btn-primary" id="rerunBtn">Re-run analysis</button>` +
+          `</div>`;
+        const rerun = document.getElementById("rerunBtn");
+        if (rerun) rerun.addEventListener("click", reprocess);
+      }
+    }
+
+    async function reprocess() {
+      if (!conversationId) {
+        location.reload();
+        return;
+      }
+      el.flow.style.display = "none";
+      el.loading.classList.add("active");
+      try {
+        const res = await authedFetch(
+          `/discovery/${conversationId}/reprocess`,
+          { method: "POST" }
+        );
+        if (!res.ok) {
+          const detail = await res
+            .json()
+            .catch(() => ({ detail: "Re-run failed" }));
+          throw new Error(detail.detail || "Re-run failed");
+        }
+        try {
+          localStorage.removeItem(STORAGE_KEY);
+        } catch (e) {
+          /* ignore */
+        }
+        window.location.href = "/static/profile.html";
+      } catch (err) {
+        el.loading.classList.remove("active");
+        el.flow.style.display = "block";
+        el.flow.innerHTML =
+          `<div class="error-box"><strong>Re-run failed.</strong><br/>` +
+          `${err.message}<br/><br/>Your answers are still saved.</div>` +
           `<div class="nav"><span></span>` +
           `<button class="btn-primary" onclick="location.reload()">Reload</button></div>`;
       }
     }
 
-    // Kick off a conversation as soon as the page loads so the id is ready.
-    startConversation().catch(() => {
+    // Resume an in-progress conversation if one exists, otherwise start a
+    // fresh one so the id is ready by submit time.
+    render();
+    resumeOrStart().catch(() => {
       /* will retry on submit */
     });
-    render();
   </script>
 </body>
 </html>