fix(adapters): ground native schemas, merge-not-replace, add goose/cagent/zed

- common/mcp.go: MCPStyle enum + BuildMCPMapStyled for claude/crush/opencode/zed dialects
- common/jsonmerge.go: MergeJSONKeys (JSON-first, JSONC fallback) preserves user keys;
  fix: try plain json.Unmarshal before StripJSONComments to avoid mangling URLs with //
- common/yamlmerge.go: MergeYAMLKeys for YAML configs (goose)
- common/blocks.go: add ProvidersAsMap for opencode map-shaped provider key
- claudecode: merge settings.json (preserves hooks/permissions/env); MCPClaudeStyle (no type field)
- crush: fix mcp key (was mcpServers); MCPCrushStyle entries include type field; merge crush.json; fix import key mcp
- kilo: drop providers key (kilo has none); MCPOpencodeStyle (local/remote); merge kilo.json
- opencode: fix provider (singular map) + model (not default_model); MCPOpencodeStyle; merge jsonc; fix import key mcp
- goose: new adapter — YAML merge, extensions map, splitProviderModel, import reconstructs MCP from extensions
- cagent: new adapter — renders starter default.yaml, import returns empty
- zed: new adapter — merge settings.json, context_servers (MCPZedStyle) + agent.default_model
- docs: append Grounded harness schemas section to design spec

internal/adapters/cagent/cagent_test.go

@@ -0,0 +1,98 @@
+package cagent
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gopkg.in/yaml.v3"
+
+	"github.com/lukaszraczylo/harness-sync/internal/adapter"
+	"github.com/lukaszraczylo/harness-sync/internal/canonical"
+)
+
+func bundle() *canonical.Bundle {
+	return &canonical.Bundle{
+		Root: "/canon",
+		Profile: canonical.Profile{
+			Gateway: canonical.Gateway{
+				URL:          "https://gw",
+				DefaultModel: "claude-sonnet-4-6",
+			},
+		},
+		Instructions: canonical.Instructions{Global: "# global instruction"},
+		MCP: canonical.MCPRegistry{Servers: []canonical.MCPServer{
+			{Name: "filepuff", Command: "/bin/filepuff", Args: []string{"--serve"}},
+		}},
+	}
+}
+
+func TestCagentRenderProducesExpectedTargets(t *testing.T) {
+	home := t.TempDir()
+	ad := New(WithHome(home))
+	fs, err := ad.Render(bundle())
+	require.NoError(t, err)
+
+	seen := map[string]adapter.File{}
+	fs.ForEach(func(f adapter.File) { seen[f.Dest] = f })
+
+	cfgDest := filepath.Join(home, ".config", "cagent", "default.yaml")
+	require.Contains(t, seen, cfgDest)
+	assert.Equal(t, adapter.RenderedFile, seen[cfgDest].Kind)
+
+	var parsed map[string]any
+	require.NoError(t, yaml.Unmarshal(seen[cfgDest].Content, &parsed))
+
+	assert.Equal(t, 8, parsed["version"])
+
+	agents := parsed["agents"].(map[string]any)
+	def := agents["default"].(map[string]any)
+	assert.Equal(t, "gateway/claude-sonnet-4-6", def["model"])
+	assert.Contains(t, def["instruction"], "# global instruction")
+
+	models := parsed["models"].(map[string]any)
+	gw := models["gateway"].(map[string]any)
+	assert.Equal(t, "openai", gw["provider"])
+	assert.Equal(t, "https://gw", gw["base_url"])
+
+	mcps := parsed["mcps"].(map[string]any)
+	fp := mcps["filepuff"].(map[string]any)
+	assert.Equal(t, "/bin/filepuff", fp["command"])
+}
+
+func TestCagentRenderNoMCP(t *testing.T) {
+	home := t.TempDir()
+	ad := New(WithHome(home))
+	b := &canonical.Bundle{
+		Profile: canonical.Profile{
+			Gateway: canonical.Gateway{URL: "https://gw", DefaultModel: "sonnet"},
+		},
+	}
+	fs, err := ad.Render(b)
+	require.NoError(t, err)
+
+	seen := map[string]adapter.File{}
+	fs.ForEach(func(f adapter.File) { seen[f.Dest] = f })
+
+	cfgDest := filepath.Join(home, ".config", "cagent", "default.yaml")
+	var parsed map[string]any
+	require.NoError(t, yaml.Unmarshal(seen[cfgDest].Content, &parsed))
+	assert.NotContains(t, parsed, "mcps")
+}
+
+func TestCagentImportReturnsEmpty(t *testing.T) {
+	ad := New(WithHome(t.TempDir()))
+	res, err := ad.Import(t.TempDir())
+	require.NoError(t, err)
+	assert.NotNil(t, res)
+	assert.Empty(t, res.MCP)
+	assert.Empty(t, res.Skills)
+	assert.Empty(t, res.Agents)
+}
+
+func TestCagentDetect(t *testing.T) {
+	home := t.TempDir()
+	ad := New(WithHome(home))
+	assert.False(t, ad.Detect())
+}