docs(releaser): release v1.5.1 — documentation site, fuzzing completeness

- Add Hugo + Geekdoc documentation site (docs/): installation, CLI
  reference, configuration, CI integration, and changelog pages; explicit
  menu bundle nav so all pages appear in the sidebar on every page
- Add Gitea CI workflow (.gitea/workflows/docs.yml): builds on push to
  main when docs/** changes, deploys minified site to gh-pages branch
- Add docs:setup / docs:serve / docs:build Taskfile tasks; theme bundle
  downloaded at build time (not committed)
- Add FuzzUpdate to internal/changelog and FuzzWriteVersion to
  internal/node to complete fuzz coverage for all file-rewriting packages
- Add fuzzing completeness guidelines to CLAUDE.md: authoritative table,
  exempt-package rationale, seed corpus rules

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

docs/content/_index.md

@@ -0,0 +1,24 @@
+---
+title: releaser
+---
+
+**CI-friendly release automation for GitFlow workflows using Conventional Commits.**
+
+Standard tools like `semantic-release` are designed for trunk-based development. In a GitFlow setup with versioned release branches (`release/1.1`, `release/1.2`), they either fail to respect the branch's version range or require brittle configuration.
+
+`releaser` is built for this exact workflow: it reads the branch name to pin the `major.minor`, parses Conventional Commits to determine the patch increment, and handles everything from `pom.xml` / `package.json` update to GitLab/GitHub tag and release creation.
+
+## How it works
+
+```
+release/1.2 branch
+  └─ last tag: 1.2.3 (or none → start at 1.2.0)
+       └─ commits since tag → Conventional Commits analysis
+            └─ next version: 1.2.4
+```
+
+1. **Branch parsing** — extracts `major.minor` from branch name (`release/1.2` → `1.2`)
+2. **Tag discovery** — finds the latest tag matching `major.minor.*` on the current branch
+3. **Commit analysis** — parses Conventional Commits between last tag and HEAD
+4. **Version bump** — increments patch (or minor, if configured via `bump_rules`)
+5. **Release** — updates `pom.xml` / `package.json`, commits, tags, creates GitLab or GitHub release