perf: Implement 2-stage map routing for faster domain lookup

Split domain routing into two stages for improved performance:
- Stage 1: map_str for exact domains (O(log n) using ebtree)
- Stage 2: map_dom for wildcards only (O(n) but small set)

Wildcards now stored in separate wildcards.map file.

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

conf/wildcards.map

@@ -0,0 +1,9 @@
+# Wildcard Domain to Backend mapping (for map_dom)
+# Format: .domain.com backend_name (matches *.domain.com)
+# Uses map_dom for suffix matching
+
+.actions.it.com pool_3
+.anvil.it.com pool_4
+.bench.inouter.com pool_5
+.mcp.inouter.com pool_2
+.nas.inouter.com pool_1