feat(gradle): release v1.6.0 — Gradle build file version bump

Add internal/gradle package with ReadVersion and WriteVersion for
build.gradle (Groovy DSL, single-quoted) and build.gradle.kts (Kotlin
DSL, double-quoted). Quote style is preserved on write. regexp.QuoteMeta
ensures version strings with dots or special characters are safe.

Config follows the established multi-value pattern:
- gradle.build_file: single path (opt-in, no default)
- gradle.build_files: list for multi-module projects (overrides build_file)
- --gradle flag overrides build_file and clears build_files

100% per-package statement coverage maintained across all 13 packages;
FuzzReadVersion and FuzzWriteVersion added per fuzzing guidelines.

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

docs/content/changelog.md

@@ -3,6 +3,23 @@ title: Changelog
 weight: 50
 ---
 
+## v1.6.0 — 2026-07-11
+
+### Added
+
+- **Gradle support** — opt-in via `gradle.build_file` (single path) or `gradle.build_files` (list, overrides single); supports both Groovy DSL (`version = '1.2.3'`) and Kotlin DSL (`version = "1.2.3"`); original quote style preserved on write; `--gradle <path>` CLI flag for one-off overrides
+
+## v1.5.1 — 2026-07-11
+
+### Added
+
+- **Documentation site** — Hugo + Geekdoc; installation, CLI reference, configuration, CI integration, and changelog pages; deployed to `gh-pages` via Gitea CI on push to `main`
+- **`FuzzUpdate`** in `internal/changelog` and **`FuzzWriteVersion`** in `internal/node` — complete fuzz coverage for all file-rewriting packages
+
+### Changed
+
+- **CLAUDE.md** — fuzzing completeness guidelines with authoritative table
+
 ## v1.5.0 — 2026-07-11
 
 ### Added