correlator/admin: capture per-scene incident_type + severity (#139)

_call_is_substanceless's "type" veto reads ctx["incident_type"] at decision
time, but that value was never persisted per-scene — only the last-scene-wins
flat field, which #138's window-4 dump analysis couldn't tell apart from
cross-scene contamination without re-guessing from a live dump. Adds
incident_type/severity to _apply_and_log's per-scene write and to admin.py's
_scene_summary allowlist (the debug-dump reader has its own field allowlist,
separate from the write side — silently would not have surfaced otherwise).

Sandboxed pytest: 380 -> 381.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Tbknwttzou4s46PAykmtix

drb-c2-core/app/routers/admin.py

@@ -109,6 +109,11 @@ async def debug_correlation(
             "scene_index":            scene_index,
             "transcript":             scene.get("transcript"),
             "incident_id":            scene.get("incident_id"),
+            # server-26#139: this scene's OWN incident_type/severity, as seen
+            # by _call_is_substanceless at decision time — not the call doc's
+            # flat top-level field, which is last-scene-wins (server-26#96).
+            "incident_type":          scene.get("incident_type"),
+            "severity":               scene.get("severity"),
             "corr_path":              corr_debug.get("corr_path"),
             "corr_incident_idle_min": corr_debug.get("corr_incident_idle_min"),
             "corr_distance_km":       corr_debug.get("corr_distance_km"),