Read the default browser from mimeapps.list when launching (#13520)

* Read the default browser from mimeapps.list when launching

omarchy-launch-browser and omarchy-launch-webapp asked xdg-settings for the
default browser on every launch, ~72ms through several POSIX shell scripts.
The new omarchy-cmd-default-browser reads the http handler from the
config-dir mimeapps.list files the way xdg-mime does, desktop-specific list
first, taking the first listed entry whose command is installed, in ~10ms.
With nothing set there it falls back to xdg-settings as before.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Let the first copy of a browser entry decide whether it is installed

A user-local entry whose browser is gone could be rescued by a system copy
of the same ID, which the launchers never read. xdg-mime judges the first
copy found, as the launchers use it, so do the same.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

test/shell.d/default-browser-lookup-test.sh

@@ -0,0 +1,72 @@
+#!/bin/bash
+
+set -euo pipefail
+
+source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/base-test.sh"
+
+test_tmp=$(mktemp -d)
+trap 'rm -rf "$test_tmp"' EXIT
+
+mock_bin="$test_tmp/bin"
+mkdir -p "$mock_bin" "$test_tmp/config" "$test_tmp/data/applications" "$test_tmp/system/applications"
+
+export HOME="$test_tmp/home"
+export XDG_CONFIG_HOME="$test_tmp/config"
+export XDG_CONFIG_DIRS="$test_tmp/etc"
+export XDG_DATA_HOME="$test_tmp/data"
+export XDG_DATA_DIRS="$test_tmp/system"
+export XDG_CURRENT_DESKTOP=Hyprland
+export BROWSER=omarchy-launch-browser
+export OMARCHY_TEST_XDG_SETTINGS_LOG="$test_tmp/xdg-settings"
+
+cat >"$mock_bin/xdg-settings" <<'SH'
+#!/bin/bash
+printf '%s\n' "${BROWSER:-unset}" >"$OMARCHY_TEST_XDG_SETTINGS_LOG"
+echo fallback.desktop
+SH
+export PATH="$mock_bin:$ROOT/bin:$PATH"
+
+for browser in chromium firefox brave; do
+  printf '#!/bin/bash\n' >"$mock_bin/$browser"
+done
+chmod +x "$mock_bin"/*
+
+echo "Exec=chromium %U" >"$XDG_DATA_HOME/applications/chromium.desktop"
+echo "Exec=firefox %u" >"$XDG_DATA_HOME/applications/firefox.desktop"
+echo "Exec=brave %U" >"$XDG_DATA_DIRS/applications/brave-browser.desktop"
+# An entry of Omarchy's own left behind by a browser since removed, shadowing
+# a system copy that the launchers would never read.
+echo "Exec=removed-browser %U" >"$XDG_DATA_HOME/applications/removed.desktop"
+echo "Exec=brave %U" >"$XDG_DATA_DIRS/applications/removed.desktop"
+
+cat >"$XDG_CONFIG_HOME/mimeapps.list" <<'EOF'
+[Added Associations]
+x-scheme-handler/http=firefox.desktop;
+
+[Default Applications]
+text/html=firefox.desktop
+x-scheme-handler/http=missing.desktop;removed.desktop;chromium.desktop;
+EOF
+
+[[ $(omarchy-cmd-default-browser) == "chromium.desktop" ]] ||
+  fail "default browser is the first installed http handler in mimeapps.list"
+[[ ! -e $OMARCHY_TEST_XDG_SETTINGS_LOG ]] ||
+  fail "default browser skips xdg-settings when mimeapps.list names one"
+
+cat >"$XDG_CONFIG_HOME/hyprland-mimeapps.list" <<'EOF'
+[Default Applications]
+x-scheme-handler/http=brave-browser.desktop
+EOF
+
+[[ $(omarchy-cmd-default-browser) == "brave-browser.desktop" ]] ||
+  fail "default browser prefers the desktop-specific mimeapps.list"
+
+rm "$XDG_CONFIG_HOME/hyprland-mimeapps.list"
+printf '[Default Applications]\nx-scheme-handler/http=missing.desktop\n' >"$XDG_CONFIG_HOME/mimeapps.list"
+
+[[ $(omarchy-cmd-default-browser) == "fallback.desktop" ]] ||
+  fail "default browser falls back to xdg-settings when no listed handler is installed"
+[[ $(<"$OMARCHY_TEST_XDG_SETTINGS_LOG") == "unset" ]] ||
+  fail "default browser unsets BROWSER before asking xdg-settings"
+
+pass "default browser reads mimeapps.list and falls back to xdg-settings"