feat(releaser): initial release v0.4.0

Complete GitFlow release automation tool for Conventional Commits workflows:

- Core pipeline: branch parsing, tag discovery, commit analysis, version bump
- Maven pom.xml read/write, git commit/tag, HTTPS push with token auth
- GitLab release creation via API with auto-generated release notes
- Configurable via .releaser.yml (tag_prefix, branch_pattern, commit_message, pom_path, gitlab)
- CLI flags: --dry-run, --no-push, --no-commit, --tag-only, --branch, --pom, --tag-prefix, --branch-pattern
- Dockerfile (multi-stage Alpine), .releaser.gitlab-ci.yml reusable template
- Gitea CI (vet + staticcheck + test + build) and release (5-platform cross-compilation) workflows
- Taskfile with build/test/cov/lint/fuzz/ci/docker tasks
- 96% test coverage with real in-memory git repos and fuzz tests for all parsers

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

internal/maven/maven.go

@@ -0,0 +1,64 @@
+package maven
+
+import (
+	"fmt"
+	"os"
+	"regexp"
+	"strings"
+)
+
+var parentBlockRe = regexp.MustCompile(`(?s)<parent>.*?</parent>`)
+var versionTagRe = regexp.MustCompile(`<version>([^<]+)</version>`)
+
+// ReadVersion returns the project version from a pom.xml file.
+// It ignores the <parent> block version and dependency versions.
+func ReadVersion(pomPath string) (string, error) {
+	data, err := os.ReadFile(pomPath)
+	if err != nil {
+		return "", fmt.Errorf("read %s: %w", pomPath, err)
+	}
+
+	// Strip <parent>…</parent> before searching so we don't pick up the parent version.
+	stripped := parentBlockRe.ReplaceAllString(string(data), "")
+
+	m := versionTagRe.FindStringSubmatch(stripped)
+	if m == nil {
+		return "", fmt.Errorf("no <version> element found in %s", pomPath)
+	}
+	return strings.TrimSpace(m[1]), nil
+}
+
+// WriteVersion replaces the project version in a pom.xml file in-place.
+// oldVersion must match what ReadVersion returned. The <parent> version is never touched.
+func WriteVersion(pomPath, oldVersion, newVersion string) error {
+	data, err := os.ReadFile(pomPath)
+	if err != nil {
+		return fmt.Errorf("read %s: %w", pomPath, err)
+	}
+
+	updated := replaceProjectVersion(string(data), oldVersion, newVersion)
+	if updated == string(data) {
+		return fmt.Errorf("version %q not found in %s", oldVersion, pomPath)
+	}
+
+	return os.WriteFile(pomPath, []byte(updated), 0644)
+}
+
+// replaceProjectVersion replaces the first <version>oldVersion</version> that is not
+// inside a <parent> block. This preserves the parent version and dependency versions.
+func replaceProjectVersion(content, oldVersion, newVersion string) string {
+	target := "<version>" + oldVersion + "</version>"
+	replacement := "<version>" + newVersion + "</version>"
+
+	// If there is a <parent> block, start searching after it.
+	if idx := strings.Index(content, "</parent>"); idx >= 0 {
+		after := content[idx:]
+		if pos := strings.Index(after, target); pos >= 0 {
+			abs := idx + pos
+			return content[:abs] + replacement + content[abs+len(target):]
+		}
+		return content
+	}
+
+	return strings.Replace(content, target, replacement, 1)
+}