Add Flatpak packaging for Sidemark (GNOME runtime, desktop metadata, docs)

README.md

@@ -56,6 +56,22 @@ Most PDF tools treat notes as an afterthought. Sidemark is built around them:
 yay -S sidemark-git
 ```
 
+### Flatpak
+
+```bash
+flatpak install flathub org.gnome.Sdk//47 org.gnome.Platform//47
+flatpak-builder --user --install --force-clean build-flatpak flatpak/de.hspitz.sidemark.yml
+flatpak run de.hspitz.sidemark
+```
+
+To open a file from the host shell:
+
+```bash
+flatpak run de.hspitz.sidemark --file-forwarding @@ /path/to/file.pdf @@
+```
+
+The Flatpak package is an additional distribution option; native `install.sh` and AUR installs are unchanged.
+
 ### install.sh (any Linux)
 
 ```bash

flatpak/de.hspitz.sidemark.metainfo.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<component type="desktop-application">
+  <id>de.hspitz.sidemark</id>
+  <metadata_license>CC0-1.0</metadata_license>
+  <project_license>MIT</project_license>
+  <name>Sidemark</name>
+  <summary>View and annotate PDF files with markdown notes</summary>
+  <launchable type="desktop-id">de.hspitz.sidemark.desktop</launchable>
+  <description>
+    <p>
+      Sidemark is a lightweight PDF annotator with a live Markdown notes panel.
+      Open PDF documents, annotate directly on pages, and keep page-linked notes.
+    </p>
+  </description>
+  <categories>
+    <category>Office</category>
+    <category>Viewer</category>
+  </categories>
+  <provides>
+    <binary>sidemark</binary>
+  </provides>
+  <releases>
+    <release version="0.2.1" date="2026-06-18" />
+  </releases>
+  <content_rating type="oars-1.1" />
+</component>

flatpak/de.hspitz.sidemark.yml

@@ -0,0 +1,31 @@
+app-id: de.hspitz.sidemark
+runtime: org.gnome.Platform
+runtime-version: '47'
+sdk: org.gnome.Sdk
+command: sidemark
+finish-args:
+  - --share=ipc
+  - --socket=wayland
+  - --socket=fallback-x11
+  - --device=dri
+  - --filesystem=home
+modules:
+  - name: python-deps
+    buildsystem: simple
+    build-commands:
+      - pip3 install --prefix=/app --no-cache-dir -r requirements.txt
+    sources:
+      - type: file
+        path: flatpak/requirements.txt
+
+  - name: sidemark
+    buildsystem: simple
+    build-commands:
+      - install -Dm755 sidemark.py /app/share/sidemark/sidemark.py
+      - install -Dm755 flatpak/sidemark-launcher /app/bin/sidemark
+      - install -Dm644 de.hspitz.sidemark.desktop /app/share/applications/de.hspitz.sidemark.desktop
+      - install -Dm644 icon.svg /app/share/icons/hicolor/scalable/apps/de.hspitz.sidemark.svg
+      - install -Dm644 flatpak/de.hspitz.sidemark.metainfo.xml /app/share/metainfo/de.hspitz.sidemark.metainfo.xml
+    sources:
+      - type: dir
+        path: .

flatpak/requirements.txt

@@ -0,0 +1,3 @@
+numpy==2.0.2
+PyMuPDF==1.26.1
+pycairo==1.28.0

flatpak/sidemark-launcher

@@ -0,0 +1,2 @@
+#!/bin/sh
+exec /usr/bin/python3 /app/share/sidemark/sidemark.py "$@"