feat: add a one-command windows build script

.gitignore

@@ -7,3 +7,5 @@ result-*
 *.db
 *.db-wal
 *.db-shm
+/dist
+carrier-windows-*.zip

README.md

@@ -53,3 +53,18 @@ The result is installed into the user flatpak and runs as
 `flatpak run com.randogoth.carrier`. Inside the sandbox the app keeps its
 config under `~/.var/app/com.randogoth.carrier/config/carrier`, so a flatpak
 install starts with a fresh identity rather than the dev build's account.
+
+### Windows
+
+Install MSYS2 (`winget install MSYS2.MSYS2`), open the **MSYS2 MINGW64**
+shell, and run the one-command script from the carrier checkout:
+
+    git clone ssh://git@code.randogoth.com:2222/randogoth/carrier.git
+    cd carrier && windows/setup.sh
+
+`windows/setup.sh` installs the GTK and Rust stack into MSYS2, clones fumi
+next to carrier if it is missing, builds, and bundles carrier.exe with the
+GTK runtime into `dist/` and a zip — the complete Windows distribution. The
+app keeps its config in `%APPDATA%\carrier`. If MSYS2 updates its core
+mid-run the shell may close; rerun the script and it continues. Cloning
+over SSH needs the key in `~/.ssh` inside the MSYS2 home.

windows/setup.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+# Windows build in one command. Run inside the MSYS2 MINGW64 shell from
+# the carrier checkout: it installs the dependencies into MSYS2, clones
+# fumi next to carrier if missing, builds, and bundles carrier plus the
+# GTK runtime into dist/ and carrier-windows.zip.
+#
+# If MSYS2 updates its own core mid-run the shell may die — just rerun.
+set -euo pipefail
+
+say() { printf '\n==> %s\n' "$*"; }
+die() { printf '\n!! %s\n' "$*" >&2; exit 1; }
+
+[ -d ../fumi/core ] || {
+    say "fumi not found next to carrier — cloning it"
+    git clone ssh://git@code.randogoth.com:2222/randogoth/fumi.git ../fumi \
+        || die "cloning fumi failed — check your SSH key in ~/.ssh"
+}
+
+say "installing dependencies (first run downloads several hundred MB)"
+pacman -Syu --noconfirm || die "pacman update failed — reopen the shell and rerun this script"
+pacman -S --noconfirm --needed \
+    mingw-w64-x86_64-gtk4 \
+    mingw-w64-x86_64-libadwaita \
+    mingw-w64-x86_64-adwaita-icon-theme \
+    mingw-w64-x86_64-toolchain \
+    mingw-w64-x86_64-rust \
+    mingw-w64-x86_64-git \
+    zip \
+    || die "installing the build stack failed"
+
+pkg-config --exists gtk4 libadwaita-1 \
+    || die "gtk4/libadwaita invisible to pkg-config — are you in the MINGW64 shell?"
+
+say "building carrier (release; the first build takes a while)"
+cargo build --release --locked || die "cargo build failed"
+
+say "bundling the runtime"
+rm -rf dist
+mkdir -p dist/share/glib-2.0/schemas \
+    dist/share/icons/hicolor/512x512/apps \
+    dist/share/icons/hicolor/256x256/apps \
+    dist/share/icons/hicolor/128x128/apps
+cp target/release/carrier.exe dist/
+for dll in $(ldd target/release/carrier.exe | awk '/mingw64/ {print $3}'); do
+    cp "$dll" dist/ || die "copying $dll failed"
+done
+[ "$(ls dist/*.dll | wc -l)" -gt 0 ] || die "no DLLs collected — ldd found none under /mingw64"
+cp /mingw64/share/glib-2.0/schemas/* dist/share/glib-2.0/schemas/
+glib-compile-schemas dist/share/glib-2.0/schemas/
+cp -r /mingw64/share/icons/Adwaita dist/share/icons/
+cp -r /mingw64/share/icons/hicolor dist/share/icons/
+cp data/icons/com.randogoth.carrier.png     dist/share/icons/hicolor/512x512/apps/
+cp data/icons/com.randogoth.carrier-256.png dist/share/icons/hicolor/256x256/apps/
+cp data/icons/com.randogoth.carrier-128.png dist/share/icons/hicolor/128x128/apps/
+
+say "zipping"
+version=$(sed -n 's/^version = "\(.*\)"$/\1/p' Cargo.toml | head -1)
+rm -f "carrier-windows-$version.zip"
+(cd dist && zip -qr "../carrier-windows-$version.zip" .)
+
+say "done — test with ./dist/carrier.exe (SmartScreen may ask once)"