posts: n8n v1→v2 migration, self-healing entitlements, TTS sidecars

Three new posts (EN + ZH twins, og + banner each):

- n8n-v1-to-v2-upgrade-gotchas (devops): the seven deprecations that
  surfaced upgrading 1.123.x → 2.40.1, decoded from the boot log —
  telemetry schema rejection, N8N_WEBHOOK_URL rename, internal runner
  deprecation, task timeout 300s→60s, two compression limits, v3
  storage rename, plus the DB override that silently disabled the
  AI sandbox.
- self-healing-digital-goods-entitlements (case-studies): the W1–W5
  NocoDB → n8n → AList entitlement lifecycle. Build-time code sharing
  for n8n Code nodes, MAX-expiry semantics, dry-run safety, daily
  drift repair, CORS-not-HMAC reasoning, and the public→internal
  NocoDB cascading-failure fix (504 → retry storm → 503).
- running-tts-as-a-service-with-token-sidecars (ai): a year-long TTS
  service built on two cron containers that refresh Azure/Google
  tokens into a shared file, with the speed/voice mapping layer.

banner-gen: center terminal body vertically so line counts shorter
than the fixed 690px panel don't leave a dead void at the bottom.
Verified via DOM measurement (gapAbove 104 / gapBelow 106).

scripts/banner-gen/template.html

@@ -64,7 +64,7 @@
   .terminal .dot.g { background: #3fb950; }
   .terminal .title-text { margin-left: 12px; color: #6b7c99; font-size: 16px; }
 
-  .terminal .body { padding: 30px 36px; font-size: 22px; line-height: 1.8; flex: 1; }
+  .terminal .body { padding: 30px 36px; font-size: 22px; line-height: 1.8; flex: 1; display: flex; flex-direction: column; justify-content: center; }
   .terminal .line { display: flex; gap: 12px; margin-bottom: 8px; }
   .terminal .prompt { color: #7599ff; flex-shrink: 0; }
   .terminal .cmd { color: #e6edf3; }