[gnacho]

What

This PR gives Foresight a real translation layer and ships the first catalogue: Spanish (Castilian). The UI is now fully translatable and translated — menus, dialogs, the capability registry, and the rsync exit-code messages.

Foresight had no i18n at all. This adds the standard GNOME/gettext setup and routes every user-facing string through it.

How

• po/ catalogue — LINGUAS, POTFILES, meson.build with i18n.gettext, and foresight.pot. Meson compiles and installs the .mo files into localedir.
• gettext-rs + domain setup — main() calls setlocale/bindtextdomain/textdomain before any widget is built, so the translatable="yes" strings in the compiled .ui (from the _("…") calls in window.blp) resolve through the same domain.
• i18n helpers (crates/foresight/src/i18n.rs) — i18n, i18n_f (positional {}), i18n_k (named {name}), ni18n, and gettext_noop for the static capability table. Rust's format! can't take a translated string as its format, so i18n_f/i18n_k do placeholder substitution after gettext.
• rsync-events now translates its exit-code messages through gettext-rs — a plain libc binding, not a GUI dependency, so the crate stays testable on any host.
• es.po — full Castilian Spanish catalogue.
• CONTRIBUTING.md — documents the translation workflow so new languages are easy to add.

Extraction

xgettext is configured with the keywords the code actually uses. The Blueprint source is extracted via --keyword=_; the Rust sources via the i18n* keywords. No --language is forced, so xgettext's C parser doesn't trip over Rust lifetimes in the .rs files (learned by measuring).

Verification

• cargo test --workspace passes (the one timing-sensitive cancel test is flaky on fast machines — pre-existing, verified against the base commit).
• cargo clippy --all-targets -- -D warnings and cargo fmt --check clean.
• Meson build, meson test (metainfo validation) and install of the .mo file verified.
• The catalogue loads at runtime: gettext resolves e.g. "Dry Run" → "Simulación", "Sync completed." → "Sincronización completada." with the installed es locale.

Suggested follow-ups (not in this PR)

These are the author's calls, so I left them out:

• A LICENSE file (the Cargo.toml and meson.build already say GPL-3.0-or-later).
• SECURITY.md, CODE_OF_CONDUCT.md and .github/ISSUE_TEMPLATE/ — standard community files for a public repo.

Closes #1

[superuser-miguel]

Thank you for this — a whole translation layer and a complete catalogue is a lot of work, and the approach (standard gettext through Meson, strings routed through helpers, CONTRIBUTING.md for the next translator) is the right one.

I want to review this a little more. There's a lot more that will be done, and it would be more work to add this now. Two things first, both my doing rather than yours:

1. It conflicts with main now. 1.0.1 landed while this was waiting and touched window.rs, job.rs, capabilities.rs and rsync-events — the same files. It also added new user-facing strings (filter-rule warnings, a confirmation dialog) that aren't in the catalogue.
2. 1.0.2 is about to touch them again with the fixes for your bug reports.

[gnacho]

Works for me. I'll hold until 1.0.2 is out, then rebase and pick up the new strings (filter-rule warnings, the confirmation dialog, whatever else lands) in a single catalogue update.