feat(usage): filter-driven Hero with cache-normalized totals

- Normalize OpenAI/Gemini input_tokens semantics in SQL via the new
  fresh_input_sql helper (cache_read subtracted at query time, no data
  migration). Recovers correct cache hit rates for Codex/Gemini.
- Add get_usage_summary_by_app endpoint for per-app split (single
  UNION ALL + GROUP BY, avoids N+1).
- Replace UsageSummaryCards + AppBreakdownRail with a single
  filter-driven UsageHero card; clicking a filter button now truly
  changes the displayed numbers and the title accent color.
- Tighten KNOWN_APP_TYPES to the 3 app_types whose token data is
  reliably collected (claude/codex/gemini); hide claude-desktop,
  hermes, opencode, openclaw filter buttons and i18n keys.
- Flag cache_creation as N/A for OpenAI-style protocols (Codex,
  Gemini); show a "partial" tooltip when the All view mixes both
  protocol families.

src/lib/api/usage.ts

@@ -1,6 +1,7 @@
 import { invoke } from "@tauri-apps/api/core";
 import type {
   UsageSummary,
+  UsageSummaryByApp,
   DailyStats,
   ProviderStats,
   ModelStats,
@@ -55,6 +56,13 @@ export const usageApi = {
     return invoke("get_usage_summary", { startDate, endDate, appType });
   },
 
+  getUsageSummaryByApp: async (
+    startDate?: number,
+    endDate?: number,
+  ): Promise<UsageSummaryByApp[]> => {
+    return invoke("get_usage_summary_by_app", { startDate, endDate });
+  },
+
   getUsageTrends: async (
     startDate?: number,
     endDate?: number,