deploy/mainnet: drop stale "DEFERRED — Do NOT compose up" banner

buyer and indexer mainnet stacks have been running on vector-marketplace
(marketplace-mainnet-buyer + marketplace-mainnet-indexer healthy, 4+ days
uptime for indexer, buyer redeployed today with the auth gate). The
"Wired but not yet exercised" header contradicts reality and would spook
the next operator who reads it.

Note in the new headers points at marketplace.vector.apexfusion.org and
mp-indexer.vector.apexfusion.org so the connection between the compose
file and the live URL is explicit. The genuinely-still-open mainnet-
safety follow-up (ARCHITECTURE.md §9 #5: env-gate / wallet allowlist /
MAINNET=1 flag) is kept as a one-line reference in the buyer header.

supplier and ollama mainnet composes are intentionally left alone — I
don't have evidence of those being deployed via these compose files.

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

deploy/mainnet/docker-compose.indexer.yml

@@ -1,11 +1,6 @@
-# MAINNET DEPLOYMENT — DEFERRED
-# Wired but not yet exercised. Mainnet rollout requires:
-#   - ARCHITECTURE.md §9 #5 (mainnet safety: env-gate, wallet allowlist, MAINNET=1 flag)
-#   - Real funded mainnet wallets
-#   - Vector mainnet ogmios stack (apex-dashboard-mainnet) running on the same host
-# Do NOT `docker compose up` until those land.
-#
 # deploy/mainnet/docker-compose.indexer.yml — Indexer (chain follower) — MAINNET
+#
+# Brought up on vector-marketplace at https://mp-indexer.vector.apexfusion.org.
 
 name: marketplace-mainnet-indexer