feat: wire Phase 7 feeds to dashboard — 7 new visualizations + nuclear map layer

Backend: add 7 new data feeds to _fetch_overview() (33 total SSE streams).
Frontend: alert banner (critical/high/medium), health outbreak tracker,
election calendar with risk bars, shipping stress gauge, social signals
from Reddit, nuclear test site map layer with concern scoring, weekly
trends with anomaly tracking. New HUD pills for alerts, shipping stress,
outbreaks, nuclear flags.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/world_intel_mcp/dashboard/app.py

@@ -35,7 +35,13 @@ from world_intel_mcp.sources import (
     intelligence,
     space_weather,
     ai_watch,
+    health,
+    elections,
+    shipping,
+    social,
+    nuclear,
 )
+from world_intel_mcp.analysis.alerts import fetch_alert_digest, fetch_weekly_trends
 
 logger = logging.getLogger(__name__)
 
@@ -91,6 +97,13 @@ async def _fetch_overview() -> dict:
         "signal_convergence": intelligence.fetch_signal_convergence(fetcher),
         "space_weather": space_weather.fetch_space_weather(fetcher),
         "ai_watch": ai_watch.fetch_ai_watch(fetcher),
+        "disease_outbreaks": health.fetch_disease_outbreaks(fetcher),
+        "election_calendar": elections.fetch_election_calendar(fetcher),
+        "shipping_index": shipping.fetch_shipping_index(fetcher),
+        "social_signals": social.fetch_social_signals(fetcher),
+        "nuclear_monitor": nuclear.fetch_nuclear_monitor(fetcher),
+        "alert_digest": fetch_alert_digest(fetcher),
+        "weekly_trends": fetch_weekly_trends(fetcher),
     }
 
     gathered = await asyncio.gather(