refactor: remove dead code, deduplicate defaultHome, simplify mcpEntry + kilo render

Dead code removed:
- BuildProviders, buildModels, ProviderEntry (no production callers)
- ZedLanguageModels (shadowed by adapter-local version, wrong schema)
- GatewayProviderID deprecated constant (zero references)
- Corresponding dead tests for BuildProviders

Deduplication:
- Extract common.DefaultHome() to internal/adapter/common/home.go
- All 7 adapters call common.DefaultHome() instead of local copies (-49 lines)

Simplification:
- mcp.go: merge MCPClaudeStyle/MCPCrushStyle branches (identical URL path,
  one-line difference in stdio path) — clearer intent, fewer lines
- kilo.go: extract opencode.jsonc merge to mergeOpenCodeJSONC() helper,
  Render() drops from 92 to ~55 lines
- goose.go: strings.IndexByte → strings.Cut in splitProviderModel

internal/adapter/common/blocks.go

@@ -11,10 +11,6 @@ import (
 
 const fallbackGatewayProviderID = "harness-sync-gateway"
 
-// GatewayProviderID is the canonical provider key used across all adapters.
-// Deprecated: prefer GatewayProviderKey(gatewayURL) for a stable URL-derived key.
-const GatewayProviderID = fallbackGatewayProviderID
-
 // GatewayProviderKey returns a stable provider key derived from the gateway URL.
 // Format: "hs-<hostname>" with dots and special chars normalised to dashes.
 // Falls back to "harness-sync-gateway" when the URL is empty or unparseable.
@@ -34,52 +30,6 @@ func GatewayProviderKey(gatewayURL string) string {
 	return "hs-" + r.Replace(host)
 }
 
-// ProviderEntry is a generic provider record. Adapters may massage further.
-type ProviderEntry = map[string]any
-
-// BuildProviders returns the canonical-to-generic provider list: gateway first
-// (if configured), then any upstreams. Each entry has id, name, base_url,
-// api_key, and (for the gateway) a models list.
-func BuildProviders(p *canonical.Profile) []ProviderEntry {
-	out := make([]ProviderEntry, 0, len(p.Upstreams)+1)
-	if p.Gateway.URL != "" {
-		key := GatewayProviderKey(p.Gateway.URL)
-		gw := ProviderEntry{
-			"id":       key,
-			"name":     "harness-sync gateway",
-			"base_url": p.Gateway.URL,
-			"api_key":  p.Gateway.Token,
-		}
-		if models := buildModels(p.Models); len(models) > 0 {
-			gw["models"] = models
-		}
-		out = append(out, gw)
-	}
-	for _, up := range p.Upstreams {
-		e := ProviderEntry{"id": up.Name, "name": up.Name}
-		if up.BaseURL != "" {
-			e["base_url"] = up.BaseURL
-		}
-		if up.APIKey != "" {
-			e["api_key"] = up.APIKey
-		}
-		out = append(out, e)
-	}
-	return out
-}
-
-func buildModels(models []canonical.Model) []map[string]any {
-	out := make([]map[string]any, 0, len(models))
-	for _, m := range models {
-		e := map[string]any{"id": m.ID}
-		if m.Alias != "" {
-			e["alias"] = m.Alias
-		}
-		out = append(out, e)
-	}
-	return out
-}
-
 // crushModel builds a 10-field model entry required by the crush schema.
 func crushModel(id string) map[string]any {
 	return map[string]any{
@@ -209,40 +159,6 @@ func ProvidersAsCagentMap(p *canonical.Profile) map[string]any {
 	return out
 }
 
-// ZedLanguageModels returns the language_models.openai block for Zed when a
-// gateway URL is configured.
-func ZedLanguageModels(p *canonical.Profile) map[string]any {
-	if p.Gateway.URL == "" {
-		return map[string]any{}
-	}
-	models := make([]map[string]any, 0)
-	for _, m := range p.Models {
-		models = append(models, map[string]any{
-			"name": m.ID,
-			"display_name": func() string {
-				if m.Alias != "" {
-					return m.Alias
-				}
-				return m.ID
-			}(),
-			"max_tokens": 8192,
-		})
-	}
-	if len(models) == 0 && p.Gateway.DefaultModel != "" {
-		models = append(models, map[string]any{
-			"name":         p.Gateway.DefaultModel,
-			"display_name": p.Gateway.DefaultModel,
-			"max_tokens":   8192,
-		})
-	}
-	return map[string]any{
-		"openai": map[string]any{
-			"api_url":          p.Gateway.URL,
-			"available_models": models,
-		},
-	}
-}
-
 // GooseCustomProviderFile returns the JSON body and provider ID for the goose
 // custom_providers/<id>.json file. Returns nil body when Gateway.URL is empty.
 func GooseCustomProviderFile(p *canonical.Profile) ([]byte, string) {

internal/adapter/common/common_test.go

@@ -9,32 +9,6 @@ import (
 	"github.com/lukaszraczylo/harness-sync/internal/canonical"
 )
 
-func TestBuildProvidersGatewayFirst(t *testing.T) {
-	p := &canonical.Profile{
-		Gateway: canonical.Gateway{URL: "https://gw", Token: "t", DefaultModel: "x"},
-		Models:  []canonical.Model{{ID: "m1", Alias: "a1"}},
-		Upstreams: []canonical.Upstream{
-			{Name: "anthropic", APIKey: "k", BaseURL: "https://api.anthropic.com"},
-		},
-	}
-	out := BuildProviders(p)
-	require.Len(t, out, 2)
-	assert.Equal(t, "hs-gw", out[0]["id"])
-	assert.Equal(t, "anthropic", out[1]["id"])
-	assert.NotNil(t, out[0]["models"])
-}
-
-func TestBuildProvidersNoGateway(t *testing.T) {
-	p := &canonical.Profile{
-		Upstreams: []canonical.Upstream{
-			{Name: "anthropic", APIKey: "k"},
-		},
-	}
-	out := BuildProviders(p)
-	require.Len(t, out, 1)
-	assert.Equal(t, "anthropic", out[0]["id"])
-}
-
 func TestBuildMCPMap(t *testing.T) {
 	reg := &canonical.MCPRegistry{Servers: []canonical.MCPServer{
 		{Name: "filepuff", Command: "/bin/x", Transport: "stdio"},

internal/adapter/common/home.go

@@ -0,0 +1,12 @@
+package common
+
+import "os"
+
+// DefaultHome returns the current user's home directory, or "" on error.
+func DefaultHome() string {
+	h, err := os.UserHomeDir()
+	if err != nil {
+		return ""
+	}
+	return h
+}

internal/adapter/common/mcp.go

@@ -31,32 +31,7 @@ func BuildMCPMapStyled(reg *canonical.MCPRegistry, style MCPStyle) map[string]an
 func mcpEntry(s canonical.MCPServer, style MCPStyle) map[string]any {
 	e := map[string]any{}
 	switch style {
-	case MCPClaudeStyle:
-		// Claude Code's actual entry shape uses "type" (not "transport").
-		// Default to stdio when no URL is set.
-		t := s.Transport
-		if s.URL != "" {
-			if t == "" {
-				t = "http"
-			}
-			e["type"] = t
-			e["url"] = s.URL
-		} else {
-			if t == "" {
-				t = "stdio"
-			}
-			e["type"] = t
-			if s.Command != "" {
-				e["command"] = s.Command
-			}
-			if len(s.Args) > 0 {
-				e["args"] = s.Args
-			}
-			if len(s.Env) > 0 {
-				e["env"] = s.Env
-			}
-		}
-	case MCPCrushStyle:
+	case MCPClaudeStyle, MCPCrushStyle:
 		if s.URL != "" {
 			t := s.Transport
 			if t == "" {
@@ -65,7 +40,12 @@ func mcpEntry(s canonical.MCPServer, style MCPStyle) map[string]any {
 			e["type"] = t
 			e["url"] = s.URL
 		} else {
-			e["type"] = "stdio"
+			// Claude honours Transport field; Crush always uses "stdio".
+			t := "stdio"
+			if style == MCPClaudeStyle && s.Transport != "" {
+				t = s.Transport
+			}
+			e["type"] = t
 			if s.Command != "" {
 				e["command"] = s.Command
 			}