fix: repair OpenCode model routing and selection (#4508)

OpenCode Zen and Go are mixed-API-surface providers — different models
behind them use different API surfaces (GPT on Zen uses codex_responses,
Claude on Zen uses anthropic_messages, MiniMax on Go uses
anthropic_messages, GLM/Kimi on Go use chat_completions).

Changes:
- Add normalize_opencode_model_id() and opencode_model_api_mode() to
  models.py for model ID normalization and API surface routing
- Add _provider_supports_explicit_api_mode() to runtime_provider.py
  to prevent stale api_mode from leaking across provider switches
- Wire opencode routing into all three api_mode resolution paths:
  pool entry, api_key provider, and explicit runtime
- Add api_mode field to ModelSwitchResult for propagation through the
  switch pipeline
- Consolidate _PROVIDER_MODELS from main.py into models.py (single
  source of truth, eliminates duplicate dict)
- Add opencode normalization to setup wizard and model picker flows
- Add opencode block to _normalize_model_for_provider in CLI
- Add opencode-zen/go fallback model lists to setup.py

Tests: 160 targeted tests pass (26 new tests covering normalization,
api_mode routing per provider/model, persistence, and setup wizard
normalization).

Based on PR #3017 by SaM13997.

Co-authored-by: SaM13997 <139419381+SaM13997@users.noreply.github.com>

hermes_cli/setup.py

@@ -114,6 +114,8 @@ _DEFAULT_PROVIDER_MODELS = {
     "minimax-cn": ["MiniMax-M2.7", "MiniMax-M2.7-highspeed", "MiniMax-M2.5", "MiniMax-M2.5-highspeed", "MiniMax-M2.1"],
     "ai-gateway": ["anthropic/claude-opus-4.6", "anthropic/claude-sonnet-4.6", "openai/gpt-5", "google/gemini-3-flash"],
     "kilocode": ["anthropic/claude-opus-4.6", "anthropic/claude-sonnet-4.6", "openai/gpt-5.4", "google/gemini-3-pro-preview", "google/gemini-3-flash-preview"],
+    "opencode-zen": ["gpt-5.4", "gpt-5.3-codex", "claude-sonnet-4-6", "gemini-3-flash", "glm-5", "kimi-k2.5", "minimax-m2.7"],
+    "opencode-go": ["glm-5", "kimi-k2.5", "minimax-m2.5", "minimax-m2.7"],
     "huggingface": [
         "Qwen/Qwen3.5-397B-A17B", "Qwen/Qwen3-235B-A22B-Thinking-2507",
         "Qwen/Qwen3-Coder-480B-A35B-Instruct", "deepseek-ai/DeepSeek-R1-0528",
@@ -189,6 +191,8 @@ def _setup_provider_model_selection(config, provider_id, current_model, prompt_c
         fetch_api_models,
         fetch_github_model_catalog,
         normalize_copilot_model_id,
+        normalize_opencode_model_id,
+        opencode_model_api_mode,
     )
 
     pconfig = PROVIDER_REGISTRY[provider_id]
@@ -242,6 +246,11 @@ def _setup_provider_model_selection(config, provider_id, current_model, prompt_c
                 f"    Use \"Custom model\" if the model you expect isn't listed."
             )
 
+    if provider_id in {"opencode-zen", "opencode-go"}:
+        provider_models = [normalize_opencode_model_id(provider_id, mid) for mid in provider_models]
+        current_model = normalize_opencode_model_id(provider_id, current_model)
+        provider_models = list(dict.fromkeys(mid for mid in provider_models if mid))
+
     model_choices = list(provider_models)
     model_choices.append("Custom model")
     model_choices.append(f"Keep current ({current_model})")
@@ -259,6 +268,8 @@ def _setup_provider_model_selection(config, provider_id, current_model, prompt_c
                 catalog=catalog,
                 api_key=api_key,
             ) or selected_model
+        elif provider_id in {"opencode-zen", "opencode-go"}:
+            selected_model = normalize_opencode_model_id(provider_id, selected_model)
         _set_default_model(config, selected_model)
     elif model_idx == len(provider_models):
         custom = prompt_fn("Enter model name")
@@ -269,6 +280,8 @@ def _setup_provider_model_selection(config, provider_id, current_model, prompt_c
                     catalog=catalog,
                     api_key=api_key,
                 ) or custom
+            elif provider_id in {"opencode-zen", "opencode-go"}:
+                selected_model = normalize_opencode_model_id(provider_id, custom)
             else:
                 selected_model = custom
             _set_default_model(config, selected_model)
@@ -300,6 +313,10 @@ def _setup_provider_model_selection(config, provider_id, current_model, prompt_c
             catalog=catalog,
             api_key=api_key,
         )
+    elif provider_id in {"opencode-zen", "opencode-go"} and selected_model:
+        model_cfg = _model_config_dict(config)
+        model_cfg["api_mode"] = opencode_model_api_mode(provider_id, selected_model)
+        config["model"] = model_cfg
 
 
 def _sync_model_from_disk(config: Dict[str, Any]) -> None: