chore(clickhouse): bring the AI_EVENTS satellite under declarative HCL

Model the AI_EVENTS role in posthog/clickhouse/hcl/ (the third managed role
after OPS and LOGS), so its schema is captured declaratively and check.sh
validates it.

Env layering follows the actual topology: local/hobby run the MSK ingest variant
(kafka_ai_events_json + ai_events_json_mv), US/EU run WarpStream
(kafka_ai_events_json_ws + ai_events_json_ws_mv, MSK dropped by migration 0248),
and prod-eu additionally carries sharded_ai_events. person/person_distinct_id2
are Distributed shims (0240) owned by the person domain and left unmanaged. dev
composes only the shared objects (per the current dump).

Goldens are generated from the layers; the local golden was verified against a
live multinode ai_events node (introspect + diff = no drift beyond the known
out-of-band set). prod-us/prod-eu goldens are authored from the captured prod
dumps.

Author: orian

posthog/clickhouse/hcl/golden/dev-ai_events.hcl

@@ -33,8 +33,18 @@ dev      logs       roles/shared roles/logs/shared roles/logs/dev
 prod-us  logs       roles/shared roles/logs/shared roles/logs/prod-us
 prod-eu  logs       roles/shared roles/logs/shared roles/logs/prod-eu
 
+# AI_EVENTS satellite (LLM analytics). Ingest objects differ by env: local/hobby
+# run the MSK variant (kafka_ai_events_json + ai_events_json_mv), US/EU run the
+# WarpStream variant (kafka_ai_events_json_ws + ai_events_json_ws_mv, MSK dropped
+# by migration 0248). person/person_distinct_id2 are Distributed shims (0240),
+# owned by the person domain and excluded from the managed set. dev currently has
+# only the shared objects (per the latest dump).
+local    ai_events  roles/shared roles/ai_events/local
+dev      ai_events  roles/shared
+prod-us  ai_events  roles/shared roles/ai_events/prod
+prod-eu  ai_events  roles/shared roles/ai_events/prod roles/ai_events/prod-eu
+
 # prod-us  data       roles/shared roles/data/shared roles/data/prod-us
 # prod-us  endpoints  roles/shared
 # prod-us  aux        roles/shared
-# prod-us  ai_events  roles/shared
 # prod-us  sessions   roles/shared