feat: Add to flatpak and snap

[ja7ad]

Preflight checklist

• I searched existing issues and this has not been proposed already.
• I checked the README and this is not already supported.

Component

Desktop GUI (Hydra Download Manager)

Problem

Currently application not available in flatpak and snap.

Proposed solution

Support build flatpak and snap then publish in flathub and snapcraft store.

Alternatives considered

No response

Platforms this should cover

• Linux
• macOS
• Windows
• Android / iOS (via libhydra)

Additional context

No response

Compatibility

• This changes existing behavior (flags, defaults, output format, or the C ABI).

Contribution

• I'm willing to open a pull request implementing this.

[SonyCore]

#132 Support for flatpak

[m4siha]

Removing the Flatpak packaging from 84c22a6 — it described a build that only worked locally and a package nobody could actually install.

The manifest built from type: dir, path: ../.., which Flathub can't use at all: its builders run offline, so a real submission needs a tagged archive source plus a generated cargo-sources.json. Past that, --filesystem=home sitting next to --share=network isn't going to survive review, and hydra-host installed into /app/bin is unreachable from a browser outside the sandbox, so the extension integration quietly doesn't work. That's a porting job, not a manifest tweak.

Leaving Flatpak and Snap to the community for now. If someone wants to own it, the app-side pieces are the interesting half — sandbox-aware update detection and a native-messaging story that survives confinement — and I'll take that PR.