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>

hermes_cli/models.py

@@ -83,6 +83,48 @@ _PROVIDER_MODELS: dict[str, list[str]] = {
         "deepseek-chat",
         "deepseek-reasoner",
     ],
+    "opencode-zen": [
+        "gpt-5.4-pro",
+        "gpt-5.4",
+        "gpt-5.3-codex",
+        "gpt-5.3-codex-spark",
+        "gpt-5.2",
+        "gpt-5.2-codex",
+        "gpt-5.1",
+        "gpt-5.1-codex",
+        "gpt-5.1-codex-max",
+        "gpt-5.1-codex-mini",
+        "gpt-5",
+        "gpt-5-codex",
+        "gpt-5-nano",
+        "claude-opus-4-6",
+        "claude-opus-4-5",
+        "claude-opus-4-1",
+        "claude-sonnet-4-6",
+        "claude-sonnet-4-5",
+        "claude-sonnet-4",
+        "claude-haiku-4-5",
+        "claude-3-5-haiku",
+        "gemini-3.1-pro",
+        "gemini-3-pro",
+        "gemini-3-flash",
+        "minimax-m2.5",
+        "minimax-m2.5-free",
+        "minimax-m2.1",
+        "glm-5",
+        "glm-4.7",
+        "glm-4.6",
+        "kimi-k2.5",
+        "kimi-k2-thinking",
+        "kimi-k2",
+        "qwen3-coder",
+        "big-pickle",
+    ],
+    "opencode-go": [
+        "glm-5",
+        "kimi-k2.5",
+        "minimax-m2.5",
+    ],
     "ai-gateway": [
         "anthropic/claude-opus-4.6",
         "anthropic/claude-sonnet-4.6",
@@ -109,6 +151,8 @@ _PROVIDER_LABELS = {
     "minimax-cn": "MiniMax (China)",
     "anthropic": "Anthropic",
     "deepseek": "DeepSeek",
+    "opencode-zen": "OpenCode Zen",
+    "opencode-go": "OpenCode Go",
     "ai-gateway": "AI Gateway",
     "custom": "Custom endpoint",
 }
@@ -125,6 +169,10 @@ _PROVIDER_ALIASES = {
     "claude": "anthropic",
     "claude-code": "anthropic",
     "deep-seek": "deepseek",
+    "opencode": "opencode-zen",
+    "zen": "opencode-zen",
+    "go": "opencode-go",
+    "opencode-go-sub": "opencode-go",
     "aigateway": "ai-gateway",
     "vercel": "ai-gateway",
     "vercel-ai-gateway": "ai-gateway",
@@ -162,6 +210,7 @@ def list_available_providers() -> list[dict[str, str]]:
     _PROVIDER_ORDER = [
         "openrouter", "nous", "openai-codex",
         "zai", "kimi-coding", "minimax", "minimax-cn", "anthropic",
+        "opencode-zen", "opencode-go",
         "ai-gateway", "deepseek", "custom",
     ]
     # Build reverse alias map