feat: multi-provider support — Ollama Cloud + OpenCode Go

- Account.Provider field (ollama-cloud | opencode-go), backward compatible
- Model-based routing: common models served by combined pool, unique models
  routed to their provider only
- /go/v1/* path forces OpenCode Go provider (prefix stripped upstream)
- Merged /v1/models endpoint returns union of both catalogs (44 models)
- Failover: 429/402 → cooldown + failover; 5xx → retry without cooldown
- CLI: accounts add --provider flag, list shows provider column
- Body buffering: request body buffered (8 MiB cap) for failover replay
- opencode integration: unified provider 'oc' with all merged models
- 64 tests pass (unit + integration)
- Verified: glm-5 → ollama, mimo-v2.5 → go, gpt-oss:20b → ollama

internal/proxy/model_router.go

@@ -0,0 +1,116 @@
+package proxy
+
+import (
+	"sort"
+
+	"github.com/Atte149/ollama-proxy/internal/config"
+)
+
+// ollamaCloudModels is the set of model IDs served by Ollama Cloud.
+// These overlap partly with the OpenCode Go catalog.
+var ollamaCloudModels = []string{
+	"deepseek-v3.1:671b", "deepseek-v3.2", "deepseek-v4-flash", "deepseek-v4-pro",
+	"devstral-2:123b", "devstral-small-2:24b",
+	"gemini-3-flash-preview", "gemma3:12b", "gemma3:27b", "gemma3:4b", "gemma4:31b",
+	"glm-4.7", "glm-5", "glm-5.1", "glm-5.2",
+	"gpt-oss:120b", "gpt-oss:20b",
+	"kimi-k2.5", "kimi-k2.6", "kimi-k2.7-code",
+	"minimax-m2.1", "minimax-m2.5", "minimax-m2.7", "minimax-m3",
+	"ministral-3:14b", "ministral-3:3b", "ministral-3:8b",
+	"mistral-large-3:675b",
+	"nemotron-3-nano:30b", "nemotron-3-super", "nemotron-3-ultra",
+	"qwen3-coder:480b", "qwen3-coder-next", "qwen3.5:397b",
+	"rnj-1:8b",
+}
+
+// openCodeGoModels is the set of model IDs served by OpenCode Go.
+var openCodeGoModels = []string{
+	"deepseek-v4-flash", "deepseek-v4-pro",
+	"glm-5", "glm-5.1", "glm-5.2",
+	"hy3-preview",
+	"kimi-k2.5", "kimi-k2.6", "kimi-k2.7-code",
+	"mimo-v2-omni", "mimo-v2-pro", "mimo-v2.5", "mimo-v2.5-pro",
+	"minimax-m2.5", "minimax-m2.7", "minimax-m3",
+	"qwen3.5-plus", "qwen3.6-plus", "qwen3.7-max", "qwen3.7-plus",
+}
+
+// modelProviders maps a model ID to the providers that can serve it.
+// Built once from the two catalogs above.
+var modelProviders = func() map[string][]config.ProviderType {
+	m := make(map[string][]config.ProviderType, len(ollamaCloudModels)+len(openCodeGoModels))
+	add := func(id string, p config.ProviderType) {
+		m[id] = append(m[id], p)
+	}
+	for _, id := range ollamaCloudModels {
+		add(id, config.ProviderOllamaCloud)
+	}
+	for _, id := range openCodeGoModels {
+		// Deduplicate: if already present (common model), append; else create.
+		found := false
+		for _, ex := range m[id] {
+			if ex == config.ProviderOpenCodeGo {
+				found = true
+				break
+			}
+		}
+		if !found {
+			add(id, config.ProviderOpenCodeGo)
+		}
+	}
+	return m
+}()
+
+// ProvidersForModel returns the providers eligible to serve the given model.
+// Unknown models default to Ollama Cloud (the original behaviour).
+func ProvidersForModel(model string) []config.ProviderType {
+	if ps, ok := modelProviders[model]; ok {
+		return ps
+	}
+	return []config.ProviderType{config.ProviderOllamaCloud}
+}
+
+// AllModels returns the deduplicated, sorted list of all model IDs known to the
+// router (union of both catalogs).
+func AllModels() []string {
+	seen := make(map[string]struct{})
+	for id := range modelProviders {
+		seen[id] = struct{}{}
+	}
+	out := make([]string, 0, len(seen))
+	for id := range seen {
+		out = append(out, id)
+	}
+	sort.Strings(out)
+	return out
+}
+
+// IsCommonModel reports whether the model is served by both providers.
+func IsCommonModel(model string) bool {
+	ps := ProvidersForModel(model)
+	if len(ps) < 2 {
+		return false
+	}
+	hasOllama, hasGo := false, false
+	for _, p := range ps {
+		switch p {
+		case config.ProviderOllamaCloud:
+			hasOllama = true
+		case config.ProviderOpenCodeGo:
+			hasGo = true
+		}
+	}
+	return hasOllama && hasGo
+}
+
+// ProviderLabel returns a short human label for a provider, used to annotate
+// unique models in the merged /v1/models response and in opencode config names.
+func ProviderLabel(p config.ProviderType) string {
+	switch p {
+	case config.ProviderOpenCodeGo:
+		return "go"
+	case config.ProviderOllamaCloud:
+		return "ollama"
+	default:
+		return string(p)
+	}
+}