chore: add prepare flathub script (#24)

Reviewed-on: #24
Co-authored-by: Ren Amamiya <reya@lume.nu>
Co-committed-by: Ren Amamiya <reya@lume.nu>

flathub/README.md

@@ -0,0 +1,129 @@
+# Flathub Submission for Coop
+
+This directory contains the files needed to submit Coop to Flathub.
+
+## Prerequisites
+
+- Flatpak installed
+- `flatpak-builder` installed
+- Rust/Cargo installed (for vendoring)
+
+## Quick Start
+
+Run the preparation script from the repo root:
+
+```bash
+./script/prepare-flathub.sh
+```
+
+This will:
+1. Vendor all Rust dependencies (crates.io + git)
+2. Generate the metainfo.xml with proper release info
+3. Create `su.reya.coop.yml` - the Flatpak manifest for Flathub
+
+## Files Generated
+
+| File | Purpose |
+|------|---------|
+| `su.reya.coop.yml` | Main Flatpak manifest (submit this to Flathub) |
+| `su.reya.coop.metainfo.xml` | AppStream metadata with release info |
+| `vendor.tar.gz` | Vendored Rust dependencies |
+| `cargo-config.toml` | Cargo configuration for offline builds |
+| `release-info.xml` | Release info snippet for metainfo |
+
+## Testing Locally
+
+Before submitting to Flathub, test the build:
+
+```bash
+cd flathub
+
+# Build and install locally
+flatpak-builder --user --install --force-clean build su.reya.coop.yml
+
+# Test the app
+flatpak run su.reya.coop
+
+# Run the Flathub linter (must pass!)
+flatpak run --command=flatpak-builder-lint org.flatpak.Builder manifest su.reya.coop.yml
+flatpak run --command=flatpak-builder-lint org.flatpak.Builder repo repo
+```
+
+## Submitting to Flathub
+
+### 1. Prepare Your Release
+
+Ensure you have:
+- [ ] Committed all changes
+- [ ] Tagged the release: `git tag -a v1.0.0-beta2 -m "Release v1.0.0-beta2"`
+- [ ] Pushed the tag: `git push origin v1.0.0-beta2`
+- [ ] Run `./script/prepare-flathub.sh` to regenerate files
+
+### 2. Fork and Submit
+
+```bash
+# Fork https://github.com/flathub/flathub on GitHub first
+
+# Clone your fork (use the new-pr branch!)
+git clone --branch=new-pr git@github.com:YOUR_USERNAME/flathub.git
+cd flathub
+
+# Create a new branch
+git checkout -b su.reya.coop
+
+# Copy ONLY the manifest file from your project
+cp /path/to/coop/flathub/su.reya.coop.yml .
+
+# Commit and push
+git add su.reya.coop.yml
+git commit -m "Add su.reya.coop"
+git push origin su.reya.coop
+```
+
+### 3. Open Pull Request
+
+1. Go to your fork on GitHub
+2. Click "Compare & pull request"
+3. **Important:** Set base branch to `new-pr` (not `master`!)
+4. Fill in the PR template
+5. Submit and wait for review
+
+## What Happens Next?
+
+1. Flathub's automated CI will build your app
+2. A maintainer will review your submission
+3. Once approved, a new repo `flathub/su.reya.coop` will be created
+4. You'll get write access to maintain the app
+5. Future updates: Push new commits to `flathub/su.reya.coop`
+
+## Updating the App
+
+To release a new version:
+
+1. Update version in workspace `Cargo.toml`
+2. Tag the new release: `git tag -a v1.0.0-beta3 -m "Release v1.0.0-beta3"`
+3. Push the tag: `git push origin v1.0.0-beta3`
+4. Run `./script/prepare-flathub.sh` to regenerate
+5. Clone the flathub repo: `git clone https://github.com/flathub/su.reya.coop.git`
+6. Update the manifest with new commit/tag and hashes
+7. Submit PR to `flathub/su.reya.coop`
+
+## Troubleshooting
+
+### Build fails with "network access not allowed"
+- Make sure `CARGO_NET_OFFLINE=true` is set in the manifest
+- Ensure `vendor.tar.gz` is properly extracted before building
+
+### Linter complains about metainfo
+- Ensure `su.reya.coop.metainfo.xml` has at least one `<release>` entry
+- Check that screenshots are accessible URLs
+
+### Missing dependencies
+- If new git dependencies are added, re-run `prepare-flathub.sh`
+- The script vendors all dependencies from `Cargo.lock`
+
+## Resources
+
+- [Flathub Submission Docs](https://docs.flathub.org/docs/for-app-authors/submission)
+- [Flatpak Manifest Reference](https://docs.flatpak.org/en/latest/manifests.html)
+- [AppStream Metainfo Guide](https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html)