tripit: enable real tour-guide content providers (wikipedia discovery, web sources, chat writer)

Viktor's tour-guide redo (tripit#24, slice tripit#25): the feature shipped
dark on 2026-06-08 because these three env vars were never set, so prod ran
the fake test-fixture providers — the only sight users ever saw was the
placeholder 'Sight 1' narrated by browser TTS. Flips discovery to Wikipedia
GeoSearch, story material to the five real web sources, and script-writing
to claude-agent-service (token already present in tripit-secrets).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

stacks/tripit/main.tf

@@ -79,6 +79,14 @@ locals {
     TTS_MODE     = "openai_compatible"
     TTS_BASE_URL = "http://chatterbox-tts.tts.svc.cluster.local:8000"
     TTS_MODEL    = "chatterbox"
+    # Tour-guide content pipeline (tripit#24/#25): these three default to `fake`
+    # in tripit's config, which is what shipped dark on 2026-06-08 — prod only
+    # ever showed the placeholder "Sight 1". Real providers: Wikipedia GeoSearch
+    # discovery, the five web story sources, and the claude-agent-service script
+    # writer (CLAUDE_AGENT_TOKEN already in tripit-secrets).
+    SIGHT_DISCOVERY_PROVIDER = "wikipedia"
+    STORY_SOURCE_MODE        = "web"
+    SCRIPT_WRITER_MODE       = "chat"
   }
 }