fix(presets): use dated Doubao model id and price 6-digit dated models

Volcengine Ark rejects the bare model name doubao-seed-2-1-pro with a 404
("model does not exist or you do not have access to it") even after the
model is activated; the API requires the full dated id
doubao-seed-2-1-pro-260628. Update the Doubao preset model id across all
apps (config default, generated catalog, and OpenClaw namespaced refs).

Pricing lookup only stripped 8-digit (YYYYMMDD) and ISO date suffixes, not
the 6-digit YYMMDD format Volcengine uses (-260628, -250615), so real
Doubao usage never matched the bare-name pricing seed and showed $0 cost.
Extend strip_model_date_suffix to also strip 6-digit YYMMDD (with
month/day validation to avoid eating non-date version suffixes), keeping
the bare-name pricing seed as the canonical identity. This also fixes
pricing for every other Volcengine Doubao model. Add unit and end-to-end
regression tests.

src/config/codexProviderPresets.ts

@@ -212,7 +212,7 @@ export const codexProviderPresets: CodexProviderPreset[] = [
     config: generateThirdPartyConfig(
       "doubaoseed",
       "https://ark.cn-beijing.volces.com/api/v3",
-      "doubao-seed-2-1-pro",
+      "doubao-seed-2-1-pro-260628",
     ),
     endpointCandidates: ["https://ark.cn-beijing.volces.com/api/v3"],
     // 火山方舟主数据面 /api/v3 原生支持 Responses API（/api/v3/responses），无需路由接管转换
@@ -221,7 +221,7 @@ export const codexProviderPresets: CodexProviderPreset[] = [
     // 让 Codex 直连显示模型并避免 custom 工具被网关拒绝
     modelCatalog: modelCatalog([
       {
-        model: "doubao-seed-2-1-pro",
+        model: "doubao-seed-2-1-pro-260628",
         displayName: "Doubao Seed 2.1 Pro",
         contextWindow: 262144,
       },