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-tauri/src/services/session_usage.rs

@@ -448,8 +448,6 @@ fn insert_session_log_entry(
         output_tokens: msg.output_tokens,
         cache_read_tokens: msg.cache_read_tokens,
         cache_creation_tokens: msg.cache_creation_tokens,
-        cache_creation_5m_tokens: 0,
-        cache_creation_1h_tokens: 0,
         model: Some(msg.model.clone()),
         message_id: None,
     };