feat(uat-batch): Group M — universal preview + field-history foundation

M42, M43 from the 2026-05-21 plan.

Shipped:
  M42  FilePreviewDialog now handles seven preview kinds via a single
       previewKindFor() router (mime + filename fallback). Image and
       PDF stay on the existing lightbox + pdf viewer; plain text
       (.txt / .md / .csv / .tsv / .json / .xml / .log / .yaml / .ini
       / .html — text/* and application/json and friends) renders via
       a new <TextPreview> that fetches via the presigned URL and
       caps the body at 1 MB with a "showing first 1 MB" banner.
       Audio / video render through native HTML5 <audio> / <video>
       elements with preload="metadata". Office documents (.docx /
       .xlsx / .pptx / .odt / .ods / .odp + the official mime variants)
       embed via Microsoft's hosted Office viewer (view.officeapps
       .live.com/op/embed.aspx) — presigned download URLs carry the
       token so the embed works without making the file world-public.
       Unknown mime types render a friendly "preview not supported"
       block with a Download CTA instead of an empty pane.
  M43  Field-level override history foundation. Migration 0081 adds
       `interest_field_history` (id, port_id, interest_id?, client_id?,
       field_path, old_value, new_value, source, submission_id?,
       created_at, created_by) with port-scoped indexes on
       (interest_id, created_at desc) and (client_id, created_at desc).
       Drizzle schema + index exports added. supplemental-forms
       applySubmission now collects an `overrides` array as it diffs
       each field against the current entity state and writes them all
       in one batch insert at the end of the transaction, so the
       rep-facing Field history panel can surface every override the
       client made via the form. New
       `GET /api/v1/interests/[id]/field-history` endpoint returns
       the rows newest-first (100-cap). Source on supplemental-info
       submissions is hardcoded to 'supplemental_form'; future
       channels (form-templates, AI extraction) drop new source
       values into the same table.

       The full form-template editor UI (Field-history panels on
       Interest + Client detail, autofill from the bound entity on
       the public form, drag-bind builder in /admin/forms) is queued
       as the next-layer follow-up; the data model + audit trail
       this commit ships are the necessary foundation for it.

Verified: tsc clean, vitest 1454/1454, migration applied.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/app/api/v1/interests/[id]/field-history/route.ts

@@ -0,0 +1,35 @@
+import { NextResponse } from 'next/server';
+import { and, desc, eq } from 'drizzle-orm';
+
+import { withAuth, withPermission } from '@/lib/api/helpers';
+import { db } from '@/lib/db';
+import { interestFieldHistory } from '@/lib/db/schema';
+import { errorResponse } from '@/lib/errors';
+
+/**
+ * GET /api/v1/interests/[id]/field-history
+ *
+ * Returns the field-level override log for the interest, newest first.
+ * Powers the "Field history" panel on Interest detail (and the matching
+ * panel on Client detail via /clients/[id]/field-history).
+ */
+export const GET = withAuth(
+  withPermission('interests', 'view', async (_req, ctx, params) => {
+    try {
+      const rows = await db
+        .select()
+        .from(interestFieldHistory)
+        .where(
+          and(
+            eq(interestFieldHistory.portId, ctx.portId),
+            eq(interestFieldHistory.interestId, params.id!),
+          ),
+        )
+        .orderBy(desc(interestFieldHistory.createdAt))
+        .limit(100);
+      return NextResponse.json({ data: rows });
+    } catch (error) {
+      return errorResponse(error);
+    }
+  }),
+);