feat: add NovitaAI as LLM provider

Add NovitaAI as a first-class provider with dedicated model selection
flow, live pricing, and authoritative context length resolution.

- Register provider in PROVIDER_REGISTRY, HERMES_OVERLAYS, and all
  alias/label maps (ID: novita, aliases: novita-ai, novitaai)
- Add dedicated _model_flow_novita() with 3-tier model list fallback:
  Novita API → models.dev → static curated list
- Fetch live pricing from /v1/models with correct unit conversion
  (input_token_price_per_m is 0.0001 USD per Mtok)
- Add Novita-specific context length resolution (step 4b) in
  get_model_context_length(), prioritized over models.dev/OpenRouter
- Register api.novita.ai in _URL_TO_PROVIDER to prevent early return
  from the custom-endpoint code path
- Add models.dev mapping (novita → novita-ai)
- Add default auxiliary model (deepseek/deepseek-v3-0324)
- Add NOVITA_API_KEY to test isolation (conftest.py)
- Update docs: providers page, env vars reference, CLI reference,
  .env.example, README, and landing page

website/docs/reference/cli-commands.md

@@ -91,7 +91,7 @@ Common options:
 | `-q`, `--query "..."` | One-shot, non-interactive prompt. |
 | `-m`, `--model <model>` | Override the model for this run. |
 | `-t`, `--toolsets <csv>` | Enable a comma-separated set of toolsets. |
-| `--provider <provider>` | Force a provider: `auto`, `openrouter`, `nous`, `openai-codex`, `copilot-acp`, `copilot`, `anthropic`, `gemini`, `google-gemini-cli`, `huggingface`, `zai`, `kimi-coding`, `kimi-coding-cn`, `minimax`, `minimax-cn`, `minimax-oauth`, `kilocode`, `xiaomi`, `arcee`, `gmi`, `alibaba`, `alibaba-coding-plan` (alias `alibaba_coding`), `deepseek`, `nvidia`, `ollama-cloud`, `xai` (alias `grok`), `qwen-oauth`, `bedrock`, `opencode-zen`, `opencode-go`, `ai-gateway`, `azure-foundry`, `lmstudio`, `stepfun`, `tencent-tokenhub` (alias `tencent`, `tokenhub`). |
+| `--provider <provider>` | Force a provider: `auto`, `openrouter`, `nous`, `openai-codex`, `copilot-acp`, `copilot`, `anthropic`, `gemini`, `google-gemini-cli`, `huggingface`, `novita`, `zai`, `kimi-coding`, `kimi-coding-cn`, `minimax`, `minimax-cn`, `minimax-oauth`, `kilocode`, `xiaomi`, `arcee`, `gmi`, `alibaba`, `alibaba-coding-plan` (alias `alibaba_coding`), `deepseek`, `nvidia`, `ollama-cloud`, `xai` (alias `grok`), `qwen-oauth`, `bedrock`, `opencode-zen`, `opencode-go`, `ai-gateway`, `azure-foundry`, `lmstudio`, `stepfun`, `tencent-tokenhub` (alias `tencent`, `tokenhub`). |
 | `-s`, `--skills <name>` | Preload one or more skills for the session (can be repeated or comma-separated). |
 | `-v`, `--verbose` | Verbose output. |
 | `-Q`, `--quiet` | Programmatic mode: suppress banner/spinner/tool previews. |

website/docs/reference/environment-variables.md

@@ -67,6 +67,8 @@ All variables go in `~/.hermes/.env`. You can also set them with `hermes config
 | `DASHSCOPE_BASE_URL` | Custom DashScope base URL (default: `https://dashscope-intl.aliyuncs.com/compatible-mode/v1`; use `https://dashscope.aliyuncs.com/compatible-mode/v1` for mainland-China region) |
 | `DEEPSEEK_API_KEY` | DeepSeek API key for direct DeepSeek access ([platform.deepseek.com](https://platform.deepseek.com/api_keys)) |
 | `DEEPSEEK_BASE_URL` | Custom DeepSeek API base URL |
+| `NOVITA_API_KEY` | NovitaAI API key — multi-model aggregator ([novita.ai/settings/key-management](https://novita.ai/settings/key-management)) |
+| `NOVITA_BASE_URL` | Override NovitaAI base URL (default: `https://api.novita.ai/openai/v1`) |
 | `NVIDIA_API_KEY` | NVIDIA NIM API key — Nemotron and open models ([build.nvidia.com](https://build.nvidia.com)) |
 | `NVIDIA_BASE_URL` | Override NVIDIA base URL (default: `https://integrate.api.nvidia.com/v1`; set to `http://localhost:8000/v1` for a local NIM endpoint) |
 | `STEPFUN_API_KEY` | StepFun API key — Step-series models ([platform.stepfun.com](https://platform.stepfun.com)) |
@@ -103,7 +105,7 @@ For native Anthropic auth, Hermes prefers Claude Code's own credential files whe
 
 | Variable | Description |
 |----------|-------------|
-| `HERMES_INFERENCE_PROVIDER` | Override provider selection: `auto`, `custom`, `openrouter`, `nous`, `openai-codex`, `copilot`, `copilot-acp`, `anthropic`, `huggingface`, `gemini`, `zai`, `kimi-coding`, `kimi-coding-cn`, `minimax`, `minimax-cn`, `minimax-oauth` (browser OAuth login — no API key required; see [MiniMax OAuth guide](../guides/minimax-oauth.md)), `kilocode`, `xiaomi`, `arcee`, `gmi`, `stepfun`, `alibaba`, `alibaba-coding-plan` (alias `alibaba_coding`), `deepseek`, `nvidia`, `ollama-cloud`, `xai` (alias `grok`), `google-gemini-cli`, `qwen-oauth`, `bedrock`, `opencode-zen`, `opencode-go`, `ai-gateway`, `tencent-tokenhub` (default: `auto`) |
+| `HERMES_INFERENCE_PROVIDER` | Override provider selection: `auto`, `custom`, `openrouter`, `nous`, `openai-codex`, `copilot`, `copilot-acp`, `anthropic`, `huggingface`, `novita`, `gemini`, `zai`, `kimi-coding`, `kimi-coding-cn`, `minimax`, `minimax-cn`, `minimax-oauth` (browser OAuth login — no API key required; see [MiniMax OAuth guide](../guides/minimax-oauth.md)), `kilocode`, `xiaomi`, `arcee`, `gmi`, `stepfun`, `alibaba`, `alibaba-coding-plan` (alias `alibaba_coding`), `deepseek`, `nvidia`, `ollama-cloud`, `xai` (alias `grok`), `google-gemini-cli`, `qwen-oauth`, `bedrock`, `opencode-zen`, `opencode-go`, `ai-gateway`, `tencent-tokenhub` (default: `auto`) |
 | `HERMES_PORTAL_BASE_URL` | Override Nous Portal URL (for development/testing) |
 | `NOUS_INFERENCE_BASE_URL` | Override Nous inference API URL |
 | `HERMES_NOUS_MIN_KEY_TTL_SECONDS` | Min agent key TTL before re-mint (default: 1800 = 30min) |