test(tools): add unit tests for error handling functions

* Implement tests for error functions like errRequiredField, errInvalidField, and errEntityNotFound.
* Ensure proper metadata is returned for various error scenarios.
* Validate error handling in CRM, Files, and other tools.
* Introduce tests for parsing stored file IDs and UUIDs.
* Enhance coverage for helper functions related to project resolution and session management.

internal/tools/version.go

@@ -0,0 +1,45 @@
+package tools
+
+import (
+	"context"
+
+	"github.com/modelcontextprotocol/go-sdk/mcp"
+
+	"git.warky.dev/wdevs/amcs/internal/buildinfo"
+)
+
+type VersionTool struct {
+	serverName string
+	info       buildinfo.Info
+}
+
+type GetVersionInfoInput struct{}
+
+type GetVersionInfoOutput struct {
+	ServerName string `json:"server_name"`
+	Version    string `json:"version"`
+	TagName    string `json:"tag_name"`
+	Commit     string `json:"commit"`
+	BuildDate  string `json:"build_date"`
+}
+
+func NewVersionTool(serverName string, info buildinfo.Info) *VersionTool {
+	return &VersionTool{
+		serverName: serverName,
+		info:       info,
+	}
+}
+
+func (t *VersionTool) GetInfo(_ context.Context, _ *mcp.CallToolRequest, _ GetVersionInfoInput) (*mcp.CallToolResult, GetVersionInfoOutput, error) {
+	if t == nil {
+		return nil, GetVersionInfoOutput{}, nil
+	}
+
+	return nil, GetVersionInfoOutput{
+		ServerName: t.serverName,
+		Version:    t.info.Version,
+		TagName:    t.info.TagName,
+		Commit:     t.info.Commit,
+		BuildDate:  t.info.BuildDate,
+	}, nil
+}