feat: detect nonstandard claude MCP server config (#728)

* feat: detect nonstandard claude configs

* code review: implement project wide scanning

* formatting

* fix project/user scope

Author: arunanshub

pkg/aitool/claude_code_user_config.go

@@ -0,0 +1,108 @@
+package aitool
+
+import (
+	"context"
+	"io/fs"
+	"os"
+	"path/filepath"
+
+	"github.com/safedep/vet/pkg/common/logger"
+)
+
+type claudeCodeUserConfigDiscoverer struct {
+	homeDir string
+	config  DiscoveryConfig
+}
+
+// NewClaudeCodeUserConfigDiscoverer creates a discoverer for Claude Code's
+// user-level MCP config (~/.claude.json) and plugin-installed MCPs
+// (~/.claude/plugins/cache/**/.mcp.json). These are distinct from app-level
+// settings (~/.claude/settings.json) handled by NewClaudeCodeDiscoverer.
+func NewClaudeCodeUserConfigDiscoverer(config DiscoveryConfig) (AIToolReader, error) {
+	homeDir := config.HomeDir
+	if homeDir == "" {
+		var err error
+		homeDir, err = os.UserHomeDir()
+		if err != nil {
+			return nil, err
+		}
+	}
+	return &claudeCodeUserConfigDiscoverer{homeDir: homeDir, config: config}, nil
+}
+
+func (d *claudeCodeUserConfigDiscoverer) Name() string { return "Claude Code User Config" }
+func (d *claudeCodeUserConfigDiscoverer) App() string  { return claudeCodeApp }
+
+func (d *claudeCodeUserConfigDiscoverer) EnumTools(_ context.Context, handler AIToolHandlerFn) error {
+	if d.config.ScopeEnabled(AIToolScopeSystem) {
+		if err := d.processUserConfig(handler); err != nil {
+			return err
+		}
+		if err := d.walkPluginCache(handler); err != nil {
+			return err
+		}
+	}
+	if d.config.ScopeEnabled(AIToolScopeProject) {
+		if err := d.processAllProjectMCPs(handler); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// processUserConfig reads ~/.claude.json, which is Claude Code's user-level
+// MCP registry. It uses the same mcpServers JSON format as settings.json.
+func (d *claudeCodeUserConfigDiscoverer) processUserConfig(handler AIToolHandlerFn) error {
+	path := filepath.Join(d.homeDir, ".claude.json")
+	cfg, err := parseMCPAppConfig(path)
+	if err != nil {
+		logger.Debugf("Claude Code user config not found or unreadable: %s", path)
+		return nil
+	}
+	return emitMCPServers(cfg, path, AIToolScopeSystem, claudeCodeApp, claudeCodeAppDisplay, handler)
+}
+
+// processAllProjectMCPs reads ~/.claude.json and emits MCP servers from every
+// entry under the "projects" map as project-scoped items (Claude Code "local"
+// scope). The ConfigPath is set to the project path so IDs are unique across
+// projects even when two projects share a server name.
+func (d *claudeCodeUserConfigDiscoverer) processAllProjectMCPs(handler AIToolHandlerFn) error {
+	path := filepath.Join(d.homeDir, ".claude.json")
+	cfg, err := parseClaudeUserConfigFile(path)
+	if err != nil {
+		logger.Debugf("Claude Code user config not found or unreadable for project MCPs: %s", path)
+		return nil
+	}
+	for projectPath, entry := range cfg.Projects {
+		if len(entry.MCPServers) == 0 {
+			continue
+		}
+		mcpCfg := projectEntryToMCPConfig(entry)
+		if err := emitMCPServers(mcpCfg, projectPath, AIToolScopeProject, claudeCodeApp, claudeCodeAppDisplay, handler); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// walkPluginCache walks ~/.claude/plugins/cache/**/.mcp.json and emits MCPs
+// from each file found. Plugin publishers use two formats: the standard
+// mcpServers-wrapped object, and a bare map of server-name to entry. Both
+// are handled via parsePluginMCPConfig.
+func (d *claudeCodeUserConfigDiscoverer) walkPluginCache(handler AIToolHandlerFn) error {
+	cacheDir := filepath.Join(d.homeDir, ".claude", "plugins", "cache")
+	return filepath.WalkDir(cacheDir, func(path string, entry fs.DirEntry, err error) error {
+		if err != nil {
+			return nil // skip inaccessible paths silently
+		}
+		if entry.IsDir() || entry.Name() != ".mcp.json" {
+			return nil
+		}
+		cfg, parseErr := parsePluginMCPConfig(path)
+		if parseErr != nil {
+			logger.Debugf("Claude Code plugin MCP config unreadable: %s: %v", path, parseErr)
+			return nil
+		}
+		return emitMCPServers(cfg, path, AIToolScopeSystem, claudeCodeApp, claudeCodeAppDisplay, handler)
+	})
+}