demo: retarget landing pages to the accounting audience

Reorients the whole sales surface to accounting so it matches the rebuilt
demos. Replaces the Shopify and RevOps persona pages with accounts-payable
(1099) and accounts-receivable pages, refreshes the bookkeeper page, and
rewires the hub + deploy tooling:

- landing/bookkeeper/  — refreshed to the validated bank-rec demo
  (26 -> 20, six phantom duplicates), iframe ?p=bookkeeper.
- landing/ap-1099/     — NEW (replaces shopify-pet/): 1099 vendor prep,
  "24 records -> 8 vendors, 7 missing EINs recovered", iframe ?p=ap-1099,
  amber accent.
- landing/ar-aging/    — NEW (replaces revops/): AR open invoices,
  "26 -> 21, five double-entered invoices removed", iframe ?p=ar-aging,
  green accent.
- landing/index.html   — hub rewritten with the three accounting cards.
- deploy.py / deploy.config.example.json / README.md / _shared/styles.css
  — persona list, sitemap defaults, 404 links, cross-links, docs updated.

All demo iframes now point at the renamed app_demo personas; deploy.py
builds the dist bundle cleanly (verified) and the Gumroad ?from= tags match.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

landing/deploy.config.example.json

@@ -11,7 +11,7 @@
   "gumroad_listing": "https://gumroad.com/l/datatools",
   "support_email":   "hello@datatools.app",
 
-  "personas": ["shopify-pet", "bookkeeper", "revops"],
+  "personas": ["bookkeeper", "ap-1099", "ar-aging"],
 
   "_substitutions_made": [
     "{{site_origin}}/                 → site_origin/",