feat(mid-section-defect): full-line bidirectional defect trace center with dual query mode

Transform /mid-section-defect from TMTT-only backward analysis into a full-line
bidirectional defect traceability center supporting all detection stations.

Key changes:
- Parameterized station detection: any workcenter group as detection station
- Bidirectional tracing: backward (upstream attribution) + forward (downstream reject rates)
- Dual query mode: date range OR LOT/工單/WAFER container-based seed resolution
- Multi-select filters for upstream station, equipment model (RESOURCEFAMILYNAME), and loss reasons
- Progressive 3-stage trace pipeline (seed-resolve → lineage → events) with streaming UI
- Equipment model lookup via resource cache instead of SPECNAME
- Session caching, auto-refresh, searchable MultiSelect with fuzzy matching
- Remove legacy tmtt-defect module (fully superseded)
- Archive openspec change artifacts

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

.env.example

@@ -161,6 +161,21 @@ CIRCUIT_BREAKER_RECOVERY_TIMEOUT=30
 # Sliding window size for counting successes/failures
 CIRCUIT_BREAKER_WINDOW_SIZE=10
 
+# ============================================================
+# Trace Pipeline Configuration
+# ============================================================
+# Slow query warning threshold (seconds) — logs warning when stage exceeds this
+TRACE_SLOW_THRESHOLD_SECONDS=15
+
+# Max parallel workers for events domain fetching (per request)
+TRACE_EVENTS_MAX_WORKERS=4
+
+# Max parallel workers for EventFetcher batch queries (per domain)
+EVENT_FETCHER_MAX_WORKERS=4
+
+# Max parallel workers for forward pipeline WIP+rejects fetching
+FORWARD_PIPELINE_MAX_WORKERS=2
+
 # ============================================================
 # Performance Metrics Configuration
 # ============================================================