revert(proxy): drop the 1-hour cache TTL option and TTL-bucketed write accounting

The forced 1-hour cache_control TTL (schema v14) was a mistake. Injected
breakpoints return to Anthropic's standard 5-minute TTL, caller-owned
markers are preserved verbatim instead of having their TTLs rewritten,
and the 5m/1h cache-write buckets are removed from usage parsing and
pricing (back to the single aggregate cache-creation rate). The cache
TTL selector is removed from the rectifier settings panel along with its
i18n keys in all four locales.

SCHEMA_VERSION returns to 13: the unreleased cache_creation_1h_tokens
column and the v13->v14 migration are removed. The feature never shipped
in a release and the introducing commit was never pushed, so no
databases were stamped v14 outside this machine (local DB verified at
user_version 13).

src/i18n/locales/ja.json

@@ -392,10 +392,7 @@
         "thinkingOptimizer": "Thinking 最適化",
         "thinkingOptimizerDescription": "Opus/Sonnet に Adaptive Thinking を自動的に有効化し、レガシーモデルに Extended Thinking を注入",
         "cacheInjection": "Cache 注入",
-        "cacheInjectionDescription": "リクエストの重要な位置に Cache ブレークポイントを自動注入し、重複トークンの課金を削減",
-        "cacheTtl": "Cache TTL",
-        "cacheTtl5m": "5 分",
-        "cacheTtl1h": "1 時間"
+        "cacheInjectionDescription": "リクエストの重要な位置に標準の 5 分間 Cache ブレークポイントを自動注入し、重複トークンの課金を削減"
       },
       "logConfig": {
         "title": "ログ管理",