Preview PDF, DOCX, XLSX & PPTX files in the browser

.gitignore

@@ -9,3 +9,6 @@
 
 # Editor / OS
 .DS_Store
+
+# Git worktrees
+/.worktrees

CHANGELOG.md

@@ -5,6 +5,15 @@ All notable changes to reefdoc are documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.9.0] - 2026-06-25
+
+### Added
+- Browse and preview binary document formats in the browser: **PDF**
+  (PDF.js), **DOCX** (docx-preview), **XLSX** (SheetJS), and **PPTX**
+  (lower fidelity). These files now appear in the file tree and open in a
+  tab as a static preview. Rendering is fully client-side; renderer
+  libraries lazy-load from CDN on first use.
+
 ## [0.8.1] - 2026-06-09
 
 ### Added

README.md

@@ -10,9 +10,9 @@ files change on disk.
 
 You edit markdown in your own editor; `reefdoc` is the preview.
 
-> **Latest release: [v0.8.1](https://github.com/exilis/reefdoc/releases/tag/v0.8.1).**
-> Recent highlights: **clicking a markdown link or an Allium `use` path opens the
-> referenced file in a new tab**; the `.claude` directory is now visible in the tree.
+> **Latest release: [v0.9.0](https://github.com/exilis/reefdoc/releases/tag/v0.9.0).**
+> Recent highlights: **PDF, DOCX, XLSX, and PPTX files now preview in the
+> browser**, rendered fully client-side.
 > Full history in the [changelog](CHANGELOG.md).
 
 ```bash
@@ -39,6 +39,7 @@ go build -o reefdoc . && ./reefdoc ./docs
 - Tabs for multiple open documents
 - GitHub-flavored markdown, code syntax highlighting, and mermaid diagrams
 - [Allium](https://allium.dev) spec files (`.allium`) rendered as formatted cards
+- Preview PDF, DOCX, XLSX, and PPTX files in the browser (rendered client-side)
 - Auto table of contents from document headings
 - Dark / light theme (mermaid follows the theme)
 - Live reload: edit a file in any editor and the open tab updates