feat(publisher): copy version from package.json and prefer mcpName in init (#1145)

## Summary

Addresses two related enhancements to `mcp-publisher init`:

- **Copy `version` from `package.json`** (#736): When `package.json` is
present and contains a `version` field, it is now used for both the
top-level `version` and `packages[].version` in the generated
`server.json`. Falls back to `"1.0.0"` when unavailable. This aligns
with the recommended best practice of keeping server version in sync
with package version.

- **Prefer `mcpName` over `name`** (#737): The init command now checks
for `mcpName` in `package.json` first, falling back to `name` if
`mcpName` is not defined. This ensures the generated server name matches
the required `mcpName` property.

Closes #736
Closes #737

## Changes

- `cmd/publisher/commands/init.go`:
- Added `getVersionFromPackageJSON()` helper to read version from
`package.json`
- Modified `InitCommand()` to use detected version with `"1.0.0"`
fallback
  - Modified `getNameFromPackageJSON()` to prefer `mcpName` over `name`

## Test plan

- [x] `go build ./cmd/publisher/...` compiles without errors
- [x] `go test ./cmd/publisher/commands/...` passes all existing tests
- [ ] Manual: run `mcp-publisher init` in a directory with
`package.json` containing `version` and `mcpName` — verify both are
copied to `server.json`
- [ ] Manual: run `mcp-publisher init` in a directory with
`package.json` without `mcpName` — verify `name` is used as fallback
- [ ] Manual: run `mcp-publisher init` in a directory without
`package.json` — verify defaults (`"1.0.0"`, directory name) are used

## AI Disclosure

AI assistance (Claude) was used for initial code exploration and issue
research. The implementation was written and reviewed by the author.

Co-authored-by: Radoslav Dimitrov <radoslav@stacklok.com>

cmd/publisher/commands/init.go

@@ -27,7 +27,10 @@ func InitCommand() error {
 	// Try to detect values from environment
 	name := detectServerName(subfolder)
 	description := detectDescription()
-	version := "1.0.0"
+	version := getVersionFromPackageJSON()
+	if version == "" {
+		version = "1.0.0"
+	}
 	repoURL := detectRepoURL()
 	repoSource := MethodGitHub
 	if repoURL != "" && !strings.Contains(repoURL, "github.com") {
@@ -140,9 +143,13 @@ func getNameFromPackageJSON() string {
 		return ""
 	}
 
-	name, ok := pkg["name"].(string)
+	// Prefer mcpName over name, as the server name must match mcpName
+	name, ok := pkg["mcpName"].(string)
 	if !ok || name == "" {
-		return ""
+		name, ok = pkg["name"].(string)
+		if !ok || name == "" {
+			return ""
+		}
 	}
 
 	// Convert npm package name to MCP server name
@@ -156,6 +163,25 @@ func getNameFromPackageJSON() string {
 	return fmt.Sprintf("io.github.<your-username>/%s", name)
 }
 
+func getVersionFromPackageJSON() string {
+	data, err := os.ReadFile("package.json")
+	if err != nil {
+		return ""
+	}
+
+	var pkg map[string]any
+	if err := json.Unmarshal(data, &pkg); err != nil {
+		return ""
+	}
+
+	version, ok := pkg["version"].(string)
+	if !ok || version == "" {
+		return ""
+	}
+
+	return version
+}
+
 func detectServerName(subfolder string) string {
 	// Try to get from git remote
 	repoURL := detectRepoURL()