feat(deepseek): switch presets to V4 (flash/pro) and add pricing

DeepSeek released V4 flash/pro; legacy IDs deepseek-chat / deepseek-reasoner
now alias to deepseek-v4-flash and will be deprecated.

- Update claude/hermes/opencode/openclaw presets to v4-pro / v4-flash,
  context 128K -> 1M; Claude Anthropic-compat endpoint routes OPUS/SONNET
  to v4-pro and HAIKU to v4-flash, plus an explicit modelsUrl override.
- Seed deepseek-v4-flash ($0.14/$0.28 per 1M) and deepseek-v4-pro
  ($1.68/$3.36 per 1M) into model_pricing; older v3.x / chat / reasoner
  rows kept for historical usage stats (INSERT OR IGNORE).
- Refresh user-manual (zh/en/ja) pricing table and note that legacy model
  IDs are billed at v4-flash rates.

src/config/hermesProviderPresets.ts

@@ -205,14 +205,14 @@ export const hermesProviderPresets: HermesProviderPreset[] = [
       api_mode: "chat_completions",
       models: [
         {
-          id: "deepseek-chat",
-          name: "DeepSeek V3.2",
-          context_length: 128000,
+          id: "deepseek-v4-pro",
+          name: "DeepSeek V4 Pro",
+          context_length: 1000000,
         },
         {
-          id: "deepseek-reasoner",
-          name: "DeepSeek R1",
-          context_length: 128000,
+          id: "deepseek-v4-flash",
+          name: "DeepSeek V4 Flash",
+          context_length: 1000000,
         },
       ],
     },
@@ -220,7 +220,7 @@ export const hermesProviderPresets: HermesProviderPreset[] = [
     icon: "deepseek",
     iconColor: "#4D6BFE",
     suggestedDefaults: {
-      model: { default: "deepseek-chat", provider: "deepseek" },
+      model: { default: "deepseek-v4-flash", provider: "deepseek" },
     },
   },
   {