Add Flatpak and Flathub packaging support

Add all files needed to package Yaak as a Flatpak for distribution on
Flathub. Uses the deb-extraction approach recommended by Tauri docs:
the manifest downloads the existing .deb release artifact, extracts it,
and installs the binary/resources into the Flatpak /app prefix.

Includes:
- AppStream metainfo.xml with app metadata and branding
- Flatpak manifest (app.yaak.desktop.yml) for x86_64 and aarch64
- Properly sized icons (128/256/512px) named per Flatpak conventions
- Helper script to update manifest hashes for new releases

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

flatpak/app.yaak.desktop.metainfo.xml

@@ -0,0 +1,69 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<component type="desktop-application">
+  <id>app.yaak.desktop</id>
+
+  <name>Yaak</name>
+  <summary>Play with APIs, intuitively</summary>
+
+  <developer id="app.yaak">
+    <name>Yaak</name>
+  </developer>
+
+  <metadata_license>MIT</metadata_license>
+  <project_license>MIT</project_license>
+
+  <url type="homepage">https://yaak.app</url>
+  <url type="bugtracker">https://github.com/mountain-loop/yaak/issues</url>
+  <url type="vcs-browser">https://github.com/mountain-loop/yaak</url>
+
+  <description>
+    <p>
+      Yaak is a cross-platform desktop app for interacting with REST, GraphQL,
+      and gRPC APIs. It provides an intuitive interface for crafting requests,
+      organizing projects, and managing environments.
+    </p>
+    <p>Features include:</p>
+    <ul>
+      <li>REST, GraphQL, and gRPC support</li>
+      <li>Environment variables and template functions</li>
+      <li>Request chaining and dynamic values</li>
+      <li>OAuth 2.0, Bearer, Basic, API Key, AWS, JWT, and NTLM authentication</li>
+      <li>Import from cURL, Postman, Insomnia, and OpenAPI</li>
+      <li>Extensible plugin system</li>
+      <li>Git-friendly project storage</li>
+    </ul>
+  </description>
+
+  <launchable type="desktop-id">app.yaak.desktop.desktop</launchable>
+
+  <branding>
+    <color type="primary" scheme_preference="light">#6e56cf</color>
+    <color type="primary" scheme_preference="dark">#7c66dc</color>
+  </branding>
+
+  <content_rating type="oars-1.1" />
+
+  <supports>
+    <control>pointing</control>
+    <control>keyboard</control>
+  </supports>
+
+  <requires>
+    <display_length compare="ge">768</display_length>
+  </requires>
+
+  <!-- TODO: Screenshots are REQUIRED for Flathub submission.
+       Host images at a stable URL (e.g. on yaak.app or in a GitHub repo).
+       Recommended: 16:9 aspect ratio, at least 1248x702, PNG format.
+       See https://docs.flathub.org/docs/for-app-authors/metainfo-guidelines/quality-guidelines -->
+  <screenshots>
+    <screenshot type="default">
+      <caption>Crafting an API request</caption>
+      <image>https://yaak.app/static/screenshots/flatpak-main.png</image>
+    </screenshot>
+  </screenshots>
+
+  <releases>
+    <!-- Releases will be added as part of the Flathub update process -->
+  </releases>
+</component>

flatpak/app.yaak.desktop.yml

@@ -0,0 +1,79 @@
+# Flatpak manifest for Yaak
+#
+# To build and test locally:
+#   flatpak install flathub org.gnome.Platform//47 org.gnome.Sdk//47
+#   flatpak-builder --force-clean --user --install-deps-from=flathub --repo=flatpak-repo build flatpak/app.yaak.desktop.yml
+#   flatpak --user remote-add --if-not-exists yaak-local flatpak-repo
+#   flatpak --user install yaak-local app.yaak.desktop
+#   flatpak run app.yaak.desktop
+
+id: app.yaak.desktop
+runtime: org.gnome.Platform
+runtime-version: "47"
+sdk: org.gnome.Sdk
+command: yaak-app
+
+finish-args:
+  # Display (Wayland + X11 fallback)
+  - --socket=wayland
+  - --socket=fallback-x11
+  - --share=ipc
+  # GPU rendering (WebKitGTK)
+  - --device=dri
+  # Network access (required — Yaak is an API client)
+  - --share=network
+  # File access for importing/exporting and Git project directories
+  - --filesystem=home
+
+modules:
+  - name: yaak
+    buildsystem: simple
+    build-commands:
+      # Extract the deb package
+      - ar -x yaak.deb
+      - tar -xf data.tar.gz
+
+      # Install the binary
+      - install -Dm755 usr/bin/yaak-app /app/bin/yaak-app
+
+      # Install bundled resources (plugins, node runtime, protoc, etc.)
+      - cp -r usr/lib/yaak /app/lib/yaak
+
+      # Install desktop file, updating Exec and Icon to match Flatpak conventions
+      - install -Dm644 usr/share/applications/yaak.desktop /app/share/applications/app.yaak.desktop.desktop
+      - desktop-file-edit --set-key=Exec --set-value=yaak-app /app/share/applications/app.yaak.desktop.desktop
+      - desktop-file-edit --set-icon=app.yaak.desktop /app/share/applications/app.yaak.desktop.desktop
+      - desktop-file-edit --set-key=StartupWMClass --set-value=yaak-app /app/share/applications/app.yaak.desktop.desktop
+
+      # Install icons from deb (small sizes) and from this repo (large sizes)
+      - install -Dm644 usr/share/icons/hicolor/32x32/apps/yaak-app.png /app/share/icons/hicolor/32x32/apps/app.yaak.desktop.png
+      - install -Dm644 usr/share/icons/hicolor/128x128/apps/yaak-app.png /app/share/icons/hicolor/128x128/apps/app.yaak.desktop.png
+      - install -Dm644 icons/256x256/app.yaak.desktop.png /app/share/icons/hicolor/256x256/apps/app.yaak.desktop.png
+      - install -Dm644 icons/512x512/app.yaak.desktop.png /app/share/icons/hicolor/512x512/apps/app.yaak.desktop.png
+
+      # Install AppStream metainfo
+      - install -Dm644 app.yaak.desktop.metainfo.xml /app/share/metainfo/app.yaak.desktop.metainfo.xml
+
+    sources:
+      # The deb package from GitHub releases
+      # Update the URL and sha256 for each release
+      - type: file
+        dest-filename: yaak.deb
+        url: https://github.com/mountain-loop/yaak/releases/download/v2026.2.0-beta.10/yaak_2026.2.0-beta.10_amd64.deb
+        sha256: "FILL_IN_SHA256_HASH"
+        only-arches:
+          - x86_64
+      - type: file
+        dest-filename: yaak.deb
+        url: https://github.com/mountain-loop/yaak/releases/download/v2026.2.0-beta.10/yaak_2026.2.0-beta.10_arm64.deb
+        sha256: "FILL_IN_SHA256_HASH"
+        only-arches:
+          - aarch64
+
+      # Icons (from this repo)
+      - type: dir
+        path: icons
+
+      # AppStream metainfo (from this repo)
+      - type: file
+        path: app.yaak.desktop.metainfo.xml

flatpak/update-manifest.sh

@@ -0,0 +1,106 @@
+#!/usr/bin/env bash
+#
+# Update the Flatpak manifest with URLs and SHA256 hashes for a given release.
+#
+# Usage:
+#   ./flatpak/update-manifest.sh v2026.2.0
+#
+# This script:
+#   1. Downloads the x86_64 and aarch64 .deb files from the GitHub release
+#   2. Computes their SHA256 checksums
+#   3. Updates the manifest YAML with the correct URLs and hashes
+#   4. Updates the metainfo.xml with a new <release> entry
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+MANIFEST="$SCRIPT_DIR/app.yaak.desktop.yml"
+METAINFO="$SCRIPT_DIR/app.yaak.desktop.metainfo.xml"
+
+if [ $# -lt 1 ]; then
+    echo "Usage: $0 <version-tag>"
+    echo "Example: $0 v2026.2.0"
+    exit 1
+fi
+
+VERSION_TAG="$1"
+VERSION="${VERSION_TAG#v}"
+REPO="mountain-loop/yaak"
+BASE_URL="https://github.com/$REPO/releases/download/$VERSION_TAG"
+
+DEB_AMD64="yaak_${VERSION}_amd64.deb"
+DEB_ARM64="yaak_${VERSION}_arm64.deb"
+
+TMPDIR=$(mktemp -d)
+trap 'rm -rf "$TMPDIR"' EXIT
+
+echo "Downloading $DEB_AMD64..."
+curl -fSL "$BASE_URL/$DEB_AMD64" -o "$TMPDIR/$DEB_AMD64"
+SHA_AMD64=$(sha256sum "$TMPDIR/$DEB_AMD64" | cut -d' ' -f1)
+echo "  SHA256: $SHA_AMD64"
+
+echo "Downloading $DEB_ARM64..."
+curl -fSL "$BASE_URL/$DEB_ARM64" -o "$TMPDIR/$DEB_ARM64"
+SHA_ARM64=$(sha256sum "$TMPDIR/$DEB_ARM64" | cut -d' ' -f1)
+echo "  SHA256: $SHA_ARM64"
+
+echo ""
+echo "Updating manifest: $MANIFEST"
+
+# Use Python for reliable YAML-like replacement (avoids sed edge cases)
+python3 << PYEOF
+import re
+
+with open("$MANIFEST", "r") as f:
+    content = f.read()
+
+# Replace x86_64 source block
+content = re.sub(
+    r'(dest-filename: yaak\.deb\n\s+url: )https://.*?\.deb(\n\s+sha256: )"[^"]*"(\n\s+only-arches:\n\s+- x86_64)',
+    rf'\g<1>${BASE_URL}/${DEB_AMD64}\2"${SHA_AMD64}"\3',
+    content,
+)
+
+# Replace aarch64 source block
+content = re.sub(
+    r'(dest-filename: yaak\.deb\n\s+url: )https://.*?\.deb(\n\s+sha256: )"[^"]*"(\n\s+only-arches:\n\s+- aarch64)',
+    rf'\g<1>${BASE_URL}/${DEB_ARM64}\2"${SHA_ARM64}"\3',
+    content,
+)
+
+with open("$MANIFEST", "w") as f:
+    f.write(content)
+
+print("  Manifest updated.")
+PYEOF
+
+echo "Updating metainfo: $METAINFO"
+
+TODAY=$(date +%Y-%m-%d)
+
+python3 << PYEOF
+import re
+
+with open("$METAINFO", "r") as f:
+    content = f.read()
+
+release_entry = f'  <releases>\n    <release version="${VERSION}" date="${TODAY}" />'
+
+# Replace existing <releases> block opening (add new release at the top)
+content = re.sub(
+    r'  <releases>\n(\s+<release )?',
+    release_entry + '\n    <release ' if '<release ' in content else release_entry + '\n',
+    content,
+    count=1,
+)
+
+with open("$METAINFO", "w") as f:
+    f.write(content)
+
+print("  Metainfo updated.")
+PYEOF
+
+echo ""
+echo "Done! Review the changes:"
+echo "  $MANIFEST"
+echo "  $METAINFO"