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/models.py

@@ -125,6 +125,12 @@ _PROVIDER_MODELS: dict[str, list[str]] = {
         "kimi-k2-turbo-preview",
         "kimi-k2-0905-preview",
     ],
+    "moonshot": [
+        "kimi-k2.5",
+        "kimi-k2-thinking",
+        "kimi-k2-turbo-preview",
+        "kimi-k2-0905-preview",
+    ],
     "minimax": [
         "MiniMax-M2.7",
         "MiniMax-M2.7-highspeed",
@@ -948,6 +954,53 @@ def copilot_model_api_mode(
     return "chat_completions"
 
 
+def normalize_opencode_model_id(provider_id: Optional[str], model_id: Optional[str]) -> str:
+    """Normalize OpenCode config IDs to the bare model slug used in API requests."""
+    provider = normalize_provider(provider_id)
+    current = str(model_id or "").strip()
+    if not current or provider not in {"opencode-zen", "opencode-go"}:
+        return current
+
+    prefix = f"{provider}/"
+    if current.lower().startswith(prefix):
+        return current[len(prefix):]
+    return current
+
+
+def opencode_model_api_mode(provider_id: Optional[str], model_id: Optional[str]) -> str:
+    """Determine the API mode for an OpenCode Zen / Go model.
+
+    OpenCode routes different models behind different API surfaces:
+
+    - GPT-5 / Codex models on Zen use ``/v1/responses``
+    - Claude models on Zen use ``/v1/messages``
+    - MiniMax models on Go use ``/v1/messages``
+    - GLM / Kimi on Go use ``/v1/chat/completions``
+    - Other Zen models (Gemini, GLM, Kimi, MiniMax, Qwen, etc.) use
+      ``/v1/chat/completions``
+
+    This follows the published OpenCode docs for Zen and Go endpoints.
+    """
+    provider = normalize_provider(provider_id)
+    normalized = normalize_opencode_model_id(provider_id, model_id).lower()
+    if not normalized:
+        return "chat_completions"
+
+    if provider == "opencode-go":
+        if normalized.startswith("minimax-"):
+            return "anthropic_messages"
+        return "chat_completions"
+
+    if provider == "opencode-zen":
+        if normalized.startswith("claude-"):
+            return "anthropic_messages"
+        if normalized.startswith("gpt-"):
+            return "codex_responses"
+        return "chat_completions"
+
+    return "chat_completions"
+
+
 def github_model_reasoning_efforts(
     model_id: Optional[str],
     *,