feat(provider): add OpenCode Zen and OpenCode Go providers

Add support for OpenCode Zen (pay-as-you-go, 35+ curated models) and
OpenCode Go ($10/month subscription, open models) as first-class providers.

Both are OpenAI-compatible endpoints resolved via the generic api_key
provider flow — no custom adapter needed.

Files changed:
- hermes_cli/auth.py — ProviderConfig entries + aliases
- hermes_cli/config.py — OPENCODE_ZEN/GO API key env vars
- hermes_cli/models.py — model catalogs, labels, aliases, provider order
- hermes_cli/main.py — provider labels, menu entries, model flow dispatch
- hermes_cli/setup.py — setup wizard branches (idx 10, 11)
- agent/model_metadata.py — context lengths for all OpenCode models
- agent/auxiliary_client.py — default aux models
- .env.example — documentation

Co-authored-by: DevAgarwal2 <DevAgarwal2@users.noreply.github.com>

agent/auxiliary_client.py

@@ -58,6 +58,8 @@ _API_KEY_PROVIDER_AUX_MODELS: Dict[str, str] = {
     "minimax-cn": "MiniMax-M2.5-highspeed",
     "anthropic": "claude-haiku-4-5-20251001",
     "ai-gateway": "google/gemini-3-flash",
+    "opencode-zen": "gemini-3-flash",
+    "opencode-go": "glm-5",
 }
 
 # OpenRouter app attribution headers

agent/model_metadata.py

@@ -80,6 +80,42 @@ DEFAULT_CONTEXT_LENGTHS = {
     "MiniMax-M2.5": 204800,
     "MiniMax-M2.5-highspeed": 204800,
     "MiniMax-M2.1": 204800,
+    # OpenCode Zen models
+    "gpt-5.4-pro": 128000,
+    "gpt-5.4": 128000,
+    "gpt-5.3-codex": 128000,
+    "gpt-5.3-codex-spark": 128000,
+    "gpt-5.2": 128000,
+    "gpt-5.2-codex": 128000,
+    "gpt-5.1": 128000,
+    "gpt-5.1-codex": 128000,
+    "gpt-5.1-codex-max": 128000,
+    "gpt-5.1-codex-mini": 128000,
+    "gpt-5": 128000,
+    "gpt-5-codex": 128000,
+    "gpt-5-nano": 128000,
+    "claude-opus-4-6": 200000,
+    "claude-opus-4-5": 200000,
+    "claude-opus-4-1": 200000,
+    "claude-sonnet-4-6": 200000,
+    "claude-sonnet-4-5": 200000,
+    "claude-sonnet-4": 200000,
+    "claude-haiku-4-5": 200000,
+    "claude-3-5-haiku": 200000,
+    "gemini-3.1-pro": 1048576,
+    "gemini-3-pro": 1048576,
+    "gemini-3-flash": 1048576,
+    "minimax-m2.5": 204800,
+    "minimax-m2.5-free": 204800,
+    "minimax-m2.1": 204800,
+    "glm-5": 202752,
+    "glm-4.7": 202752,
+    "glm-4.6": 202752,
+    "kimi-k2.5": 262144,
+    "kimi-k2-thinking": 262144,
+    "kimi-k2": 262144,
+    "qwen3-coder": 32768,
+    "big-pickle": 128000,
 }