Add sync-help-from-civi script + field-group rendering

Two additions, both touching the form-config story:

1. scripts/sync-help-from-civi.mjs

   Diffs per-field help text in config/form.ts against CustomField rows
   in CiviCRM and (with --write) updates the file in place. Reads env
   from .env.local via Node's --env-file flag. Run as `npm run sync-help`
   or `npm run sync-help -- --write`. A --debug mode prints the parser's
   field list without calling Civi.

   Rationale: this form is low-traffic and help text doesn't change
   often once in production. A manual one-off sync is leaner than
   coupling every page load (or every build) to a Civi API call.

2. fieldGroups: visual clustering of related fields within a section

   New optional FieldGroupConfig overlay on StageSectionConfig — pure
   presentation, names existing fields by name so submit/visibility
   logic walks them unchanged. StageSection.tsx pulls grouped fields
   out of the standalone per-field grid and renders each group as its
   own bordered card with an optional heading. Stage 2 now clusters
   Market Study, Pro Forma, Business Plan, and Board Self Assessment
   (each a date + upload pair) into their own cards.

package.json

@@ -6,7 +6,8 @@
     "dev": "next dev",
     "build": "next build",
     "start": "next start",
-    "lint": "eslint"
+    "lint": "eslint",
+    "sync-help": "node --env-file=.env.local scripts/sync-help-from-civi.mjs"
   },
   "dependencies": {
     "next": "16.2.6",