fix: reload sentiment cycle history after backfill

backfillData() only refreshed system settings after a successful backfill,
leaving state.sentimentHistory/sentimentHistoryKey populated with the stale
pre-backfill cache, so an already-open sentiment cycle page kept showing the
old one-day history.

After a successful backfill, clear both cache fields and, when the sentiment
cycle view is active, force loadSentimentHistory(true) so the history renders
immediately. Add a frontend contract test covering the refresh path.

Co-authored-by: multica-agent <github@multica.ai>

app/config/architecture-inventory.json

@@ -541,8 +541,8 @@
     },
     {
       "path": "frontend/shared/admin.js",
-      "bytes": 14386,
-      "lines": 265
+      "bytes": 14556,
+      "lines": 270
     },
     {
       "path": "backend/features/heaven/market_context.py",