Filter out planned and part closures from TFL alerts

Only show active disruptions (delays, suspensions), not planned
closures which aren't relevant for real-time commute decisions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

IrisCompanion/iris/DataSources/TFLDataSource.swift

@@ -99,10 +99,12 @@ final class TFLDataSource {
             guard !seenLines.contains(line.id) else { continue }
 
             for status in line.lineStatuses {
+                // Skip: 10 = Good Service, 4 = Planned Closure, 5 = Part Closure
                 guard status.statusSeverity < 10 else { continue }
+                guard status.statusSeverity != 4 && status.statusSeverity != 5 else { continue }
 
                 seenLines.insert(line.id)
-                let isMajor = status.statusSeverity <= 6
+                let isMajor = status.statusSeverity <= 3 || status.statusSeverity == 6
 
                 let disruption = Disruption(
                     id: "\(line.id):\(status.statusSeverity)",