feat(releaser): release v1.5.0 — Node.js, multi-module Maven, configurable bump rules

- Add internal/node package: reads/writes package.json version (single or
  multi-path via node.package_json / node.package_jsons)
- Add maven.pom_paths support: update multiple pom.xml files in one release
  commit; pom_paths overrides pom_path; --pom flag clears pom_paths
- Add git.bump_rules config: per-type control of which version component bumps
  (breaking/feat/fix accept "patch" or "minor"); wired through version.Next()
  as a new sixth parameter
- Extract injectable function vars (absPath, gitAllCommits, gitCommitsSince,
  gitCommitFiles) to enable error-path testing without interfaces
- Achieve 100% per-package statement coverage across all 12 packages

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/node/node.go

@@ -0,0 +1,42 @@
+package node
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+)
+
+// ReadVersion returns the version field from a package.json file.
+func ReadVersion(path string) (string, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return "", fmt.Errorf("read %s: %w", path, err)
+	}
+	var pkg struct {
+		Version string `json:"version"`
+	}
+	if err := json.Unmarshal(data, &pkg); err != nil {
+		return "", fmt.Errorf("parse %s: %w", path, err)
+	}
+	if pkg.Version == "" {
+		return "", fmt.Errorf("no version field in %s", path)
+	}
+	return pkg.Version, nil
+}
+
+// WriteVersion replaces the version field in a package.json file in-place.
+// oldVersion must match what ReadVersion returned. Formatting is preserved.
+func WriteVersion(path, oldVersion, newVersion string) error {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return fmt.Errorf("read %s: %w", path, err)
+	}
+	old := `"version": "` + oldVersion + `"`
+	repl := `"version": "` + newVersion + `"`
+	if !strings.Contains(string(data), old) {
+		return fmt.Errorf("version %q not found in %s", oldVersion, path)
+	}
+	updated := strings.Replace(string(data), old, repl, 1)
+	return os.WriteFile(path, []byte(updated), 0644)
+}