healthcare emails: remove prices, fix click tracking, de-risk claims

Diagnosing zero healthcare sales (11k sent, 5479 opens, 0 clicks, 0 orders).
Root cause of clicks=0: Listmonk only registers a link for tracking when the
href ends with the literal @TrackLink marker; all 10 hc templates lacked it
(trucking/CRTC have it). So the entire funnel was unmeasurable below 'open'.

Changes:
- Click tracking: append @TrackLink + UTM to every /order/ CTA across all 10
  templates (external gov self-verify links left untracked on purpose).
- Remove all service prices from emails (99/49/49/99yr/9mo). Price is
  now revealed on the order page after value is established; catalog
  (api/src/service-catalog.ts) stays source of truth. Kept the 0,000 OIG
  penalty stat (regulatory fact, not our price). Added a neutral 'flat fee shown
  up front' reassurance block where the fee table used to be.
- Compliance/honesty: the nppes_outdated email asserted a per-record
  'FLAGGED OUT OF DATE / detected' status, but its selector only checks
  deliverability and the data has no NPPES last-updated field -> unsubstantiated
  for every recipient. Reframed to a generally-true periodic-attestation message
  ('PERIODIC REVIEW REQUIRED', 'most practices drift out of date'). Same hedging
  applied to npi_reactivation ('may be deactivated ... confirm on official
  sources'). Substantiated reval 'past due' claims (backed by the public CMS
  Revalidation list) were kept.
- Fixed stale $299 OIG metadata in build script -> $79/mo (reference only).

Docs: docs/healthcare-competitive-pricing.md (benchmark research) and
docs/healthcare-email-compliance-review.md (CAN-SPAM / FTC / impersonation pass;
flags SOC2/HIPAA/PCI badge claims for owner confirmation).

Verified headless: all 10 render with 0 JS errors, exactly 1 tracked CTA each,
no price leaks.

scripts/build_healthcare_campaigns.py

@@ -45,7 +45,9 @@ OUT_DIR = os.path.join(os.path.dirname(__file__), "..", "data", "hc_campaigns")
 #   subject        listmonk campaign subject line
 #   template       HTML file under data/hc_campaigns/ (the canonical body)
 #   cta_path       order page the CTA links to (NPI appended as ?npi=)
-#   price          headline price (for reference / docs; lives in the template)
+#   price          reference price only (catalog in api/src/service-catalog.ts is
+#                  the source of truth). NOT shown in the email anymore — price is
+#                  revealed on the order page after the value is established.
 #   list_name      listmonk-hc list this segment is warmed into
 #   campaign_name  listmonk-hc campaign name prefix (dated per build)
 #   selector       which warmup-CSV rows belong to this segment (see cron)
@@ -90,7 +92,7 @@ SEGMENTS = {
         "subject": "Are you screening for OIG / SAM exclusions?",
         "template": "hc_oig_screening.html",
         "cta_path": "/order/oig-sam-screening",
-        "price": "$299",
+        "price": "$79/mo",
         "list_name": "HC Warmup - OIG Screening",
         "campaign_name": "HC Warmup - OIG Screening",
         "selector": "institutional_verified",