feat: edit parsed records before importing

The import preview only showed counts + skipped-row errors with no way to
fix anything. Now every parsed record is editable before import:

- backend: shared validatePatientImport() (used by the previewImport tool)
  + POST /api/ai/import/validate for dry-run re-validation; the import
  preview payload now carries the original records (and the source record on
  each invalid row) so the UI can edit them.
- frontend: the import card gets a "Review & edit" dialog listing every
  record with a ready / needs-fixing badge; opening one reuses the full
  PatientFormDialog in a new non-persisting review mode (editable file
  number) and re-validates on save, so skipped rows can be fixed and
  included.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/src/routes/ai.ts

@@ -18,6 +18,7 @@ import {
   saveAiConfig,
   toAiConfig,
 } from "../services/ai/config.js";
+import { validatePatientImport } from "../services/ai/import.js";
 import { getPolicy, savePolicy } from "../services/ai/policy.js";
 import * as patients from "../services/patients.js";
 
@@ -189,3 +190,27 @@ aiRouter.post(
     }
   },
 );
+
+// --- Migration import re-validation (dry run) -------------------------------
+// Powers the "review & edit before import" UI: the client edits parsed records
+// and calls this to refresh which are ready vs. need fixing. Writes nothing.
+aiRouter.post(
+  "/import/validate",
+  requireAuth,
+  requireOrg,
+  requirePermission({ patient: ["write"] }),
+  async (req, res, next) => {
+    try {
+      const records = (req.body as { records?: unknown[] }).records;
+      if (!Array.isArray(records)) {
+        throw new HttpError(400, "records must be an array.");
+      }
+      if (records.length > 500) {
+        throw new HttpError(400, "Too many records (max 500).");
+      }
+      res.json(validatePatientImport(records));
+    } catch (err) {
+      next(err);
+    }
+  },
+);