feat(routing)!: task rules become per-complexity model maps

The single per-task «Complexity» pin was the wrong shape — what you actually
decide is WHICH model serves a task at WHICH complexity. A task rule is now a
per-tier map, edited in the console as rows of “model ▾ + complexity ▾” pairs
(plus ×/add) inside each task:

  [routing.tasks.code]
  low  = ["cheap-coder"]
  high = ["best-coder"]
  any  = ["generic-coder"]   # leads at every tier after the tier pick

Chain order: the task's tier-specific list → (at high: the global high chain,
so escalation still beats any-tier pins) → the task's any-tier list → the
global tier chain → default as the last resort; deduplicated. Plain-array
rules keep meaning "any tier" unchanged, and the short-lived {models, tier}
form from the previous commit is normalized into the map on load.

Verified live: legacy config migrated visibly in the editor, pairs survive
save+reload, a math prompt at low ignored the math@high pair, per-tier leads
confirmed by unit tests (19 passing).

web/js/i18n/de.js

@@ -626,5 +626,7 @@ export default {
   "keys.col.costAll": "$ gesamt",
   "routing.tasks.tier": "Komplexität",
   "routing.tasks.tierAuto": "Auto (Router)",
-  "routing.tasks.tierHint": "Komplexität für diese Aufgabe festlegen: das Router-Urteil wird ersetzt, high eskaliert weiterhin über die Modellliste.",
+  "routing.tasks.tierHint": "Welches Modell diese Aufgabe bei welcher Komplexität bedient; \"jede\" führt auf allen Stufen. Reihenfolge = Fallback-Reihenfolge. High eskaliert weiterhin über \"jede\"-Einträge.",
+  "routing.tasks.tierAny": "jede Komplexität",
+  "routing.tasks.addModel": "Modell",
 };

web/js/i18n/en.js

@@ -619,5 +619,7 @@ export default {
   "keys.col.costAll": "$ all-time",
   "routing.tasks.tier": "Complexity",
   "routing.tasks.tierAuto": "Auto (router)",
-  "routing.tasks.tierHint": "Pin the complexity tier for this task: the router's verdict is replaced, high still escalates over the model list.",
+  "routing.tasks.tierHint": "Which model serves this task at which complexity; \"any\" leads at every tier. Order = fallback order. High verdicts still escalate over any-tier pins.",
+  "routing.tasks.tierAny": "any complexity",
+  "routing.tasks.addModel": "model",
 };

web/js/i18n/es.js

@@ -626,5 +626,7 @@ export default {
   "keys.col.costAll": "$ total",
   "routing.tasks.tier": "Complejidad",
   "routing.tasks.tierAuto": "Auto (router)",
-  "routing.tasks.tierHint": "Fijar la complejidad de esta tarea: el veredicto del router se sustituye, high sigue escalando por encima de la lista de modelos.",
+  "routing.tasks.tierHint": "Qué modelo atiende esta tarea en qué complejidad; «cualquiera» lidera en todos los niveles. El orden = orden de respaldo. Un veredicto high sigue escalando sobre las entradas «cualquiera».",
+  "routing.tasks.tierAny": "cualquier complejidad",
+  "routing.tasks.addModel": "modelo",
 };

web/js/i18n/fr.js

@@ -626,5 +626,7 @@ export default {
   "keys.col.costAll": "$ au total",
   "routing.tasks.tier": "Complexité",
   "routing.tasks.tierAuto": "Auto (routeur)",
-  "routing.tasks.tierHint": "Fixer la complexité de cette tâche : le verdict du routeur est remplacé, high continue d'escalader au-dessus de la liste de modèles.",
+  "routing.tasks.tierHint": "Quel modèle sert cette tâche à quelle complexité ; « toute » mène à tous les niveaux. L'ordre = ordre de repli. Un verdict high escalade toujours au-dessus des entrées « toute ».",
+  "routing.tasks.tierAny": "toute complexité",
+  "routing.tasks.addModel": "modèle",
 };

web/js/i18n/ru.js

@@ -618,5 +618,7 @@ export default {
   "keys.col.costAll": "$ за всё время",
   "routing.tasks.tier": "Сложность",
   "routing.tasks.tierAuto": "Авто (по роутеру)",
-  "routing.tasks.tierHint": "Закрепить уровень сложности для задачи: вердикт роутера заменяется, high по-прежнему эскалирует поверх списка моделей.",
+  "routing.tasks.tierHint": "Какая модель обслуживает задачу на какой сложности; «любая» ведёт на всех уровнях. Порядок = порядок фолбэка. Вердикт high по-прежнему эскалирует поверх «любых».",
+  "routing.tasks.tierAny": "любая сложность",
+  "routing.tasks.addModel": "модель",
 };

web/js/i18n/tr.js

@@ -626,5 +626,7 @@ export default {
   "keys.col.costAll": "$ toplam",
   "routing.tasks.tier": "Karmaşıklık",
   "routing.tasks.tierAuto": "Otomatik (yönlendirici)",
-  "routing.tasks.tierHint": "Bu görev için karmaşıklık katmanını sabitle: yönlendiricinin kararı değiştirilir, high yine model listesinin üzerine tırmanır.",
+  "routing.tasks.tierHint": "Bu görevi hangi karmaşıklıkta hangi model karşılar; \"her\" tüm katmanlarda önde gider. Sıra = yedekleme sırası. High kararı \"her\" girdilerinin üzerine yine tırmanır.",
+  "routing.tasks.tierAny": "her karmaşıklık",
+  "routing.tasks.addModel": "model",
 };

web/js/i18n/zh.js

@@ -626,5 +626,7 @@ export default {
   "keys.col.costAll": "$ 累计",
   "routing.tasks.tier": "复杂度",
   "routing.tasks.tierAuto": "自动（路由器）",
-  "routing.tasks.tierHint": "为该任务固定复杂度层级：替换路由器的判断，high 仍会越过模型列表进行升级。",
+  "routing.tasks.tierHint": "哪个模型在哪个复杂度上处理该任务；「任意」在所有层级领先。顺序即回退顺序。high 判定仍会越过「任意」条目升级。",
+  "routing.tasks.tierAny": "任意复杂度",
+  "routing.tasks.addModel": "模型",
 };