feat(models): add deepseek-v4-pro and deepseek-v4-flash (#14934)

- OpenRouter: deepseek/deepseek-v4-pro, deepseek/deepseek-v4-flash
- Nous Portal (fallback list): same two slugs
- Native DeepSeek provider: bare deepseek-v4-pro, deepseek-v4-flash
  alongside existing deepseek-chat/deepseek-reasoner

Context length resolves via existing 'deepseek' substring entry (128K)
in DEFAULT_CONTEXT_LENGTHS.

hermes_cli/models.py

@@ -33,6 +33,8 @@ COPILOT_REASONING_EFFORTS_O_SERIES = ["low", "medium", "high"]
 # (model_id, display description shown in menus)
 OPENROUTER_MODELS: list[tuple[str, str]] = [
     ("moonshotai/kimi-k2.6",            "recommended"),
+    ("deepseek/deepseek-v4-pro",        ""),
+    ("deepseek/deepseek-v4-flash",      ""),
     ("anthropic/claude-opus-4.7",       ""),
     ("anthropic/claude-opus-4.6",       ""),
     ("anthropic/claude-sonnet-4.6",     ""),
@@ -109,6 +111,8 @@ def _codex_curated_models() -> list[str]:
 _PROVIDER_MODELS: dict[str, list[str]] = {
     "nous": [
         "moonshotai/kimi-k2.6",
+        "deepseek/deepseek-v4-pro",
+        "deepseek/deepseek-v4-flash",
         "xiaomi/mimo-v2.5-pro",
         "xiaomi/mimo-v2.5",
         "anthropic/claude-opus-4.7",
@@ -246,6 +250,8 @@ _PROVIDER_MODELS: dict[str, list[str]] = {
         "claude-haiku-4-5-20251001",
     ],
     "deepseek": [
+        "deepseek-v4-pro",
+        "deepseek-v4-flash",
         "deepseek-chat",
         "deepseek-reasoner",
     ],