feat: add Zenith strategy and move latency tracing

- Register Zenith 1.1 with balanced duel verdicts and forced-outcome overrides.
- Prioritize permanent-trail space in Constrictor and health-aware hazard routes.
- Deduct executor queue delays and return fallback directions on move timeouts.
- Correlate response headers, replay timings, and sampled structured trace logs.
- Move shared metrics publication off the response path without losing local counts.
- Allow configurable tournament opponents and add a psql helper recipe.
- Preserve empty latency values through compact replay encoding and migration.
- Update Arena game links and use default assets for missing customizations.
- Cover strategy, HTTP lifecycle, tracing, replay codecs, and dashboard behavior.
- Validate with 260 passing Python tests, 4 skips, and 2 passing JavaScript tests.

dbschema/default.gel

@@ -3,7 +3,7 @@ module default {
     using (winner = "me");
 
   function gameboard_url(id: uuid) -> str
-    using ("https://play.battlesnake.com/game/" ++ <str>id);
+    using ("https://arena.battlesnake.com/games/" ++ <str>id);
 
   type GameBoard {
     overloaded required id: uuid {