correlator: mirror the dispatch/tactical idle split in the escape hatch, record the gate-veto reason (#115)

Review of #126 found: (1) the escape hatch applied tg_dispatch_thin_idle_minutes (5 min) unconditionally, but incident_correlator's own fast/thin path only uses that on dispatch channels and 15 min on tactical ones via _is_dispatch_channel -- mirrored the same selection here, plus a config.py note flagging the second consumer. (2) the docstring claimed a 'confirmed explanation' for 2 window-3 gate misses that was actually wrong (self-contradictory in its own text); replaced the guess with corr_gate_veto, written into corr_debug on every llm=orphan/rules=new disagreement that escalates, so window #4 can see *why* each one escaped instead of reconstructing it from the raw dump.

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

Claude-Session: https://claude.ai/code/session_01Tbknwttzou4s46PAykmtix

drb-c2-core/app/config.py

@@ -97,6 +97,11 @@ class Settings(BaseSettings):
     # Across that dump every correct thin attach was <= 3.4 min idle and every wrong
     # one was >= 8.2, so 5 separates them with room on both sides. Genuine
     # back-and-forth is handled by the 30-second tier-1 path above this.
+    # Second consumer (server-26#115): routers/upload.py's LLM-orphan-gate escape
+    # hatch (_recent_incident_on_same_talkgroup) reuses this same value, selected
+    # the same way (dispatch vs tactical) via _is_dispatch_channel. Retuning this
+    # for fast/thin reasons moves that gate's behavior too — check both call
+    # sites before changing it.
     tg_dispatch_thin_idle_minutes: int = 5
     # Every other channel: tier-2 thin calls attach to a lone candidate idle < this.
     # Non-dispatch talkgroups previously had NO tier-2 bound at all — they used the