feat(blankpad): desk.sh profile switcher, hotplug autoswitch daemon, keybinds doc generator + bats suite

- desk.sh: list/current/switch/cycle/match/capture over cfg/desk-*.kdl
  profiles; apply = relink display.kdl, niri validate (rollback on fail),
  load-config-file, noctalia notification; match scores // requires: lines
  (EDID long names) against live niri msg outputs
- desk-autoswitch.sh: watch niri msg --json event-stream for
  OutputsChanged, debounced desk.sh match --apply, reconnect loop
- blankpad-desk-autoswitch.service: ConditionHost=blankpad user unit
- gen-keybinds.sh: keybinds.kdl -> markdown cheat sheet (sections from
  // --- headers, hotkey-overlay-title preferred over action)
- tests/: 27 bats cases, all green (desk 16, gen-keybinds 6,
  niri-config 5 incl. real niri validate on the assembled tree with
  each desk profile active)

scripts/desk.sh

@@ -0,0 +1,166 @@
+#!/usr/bin/env bash
+# scripts/desk.sh — Desk profile management for niri (blankpad)
+#
+# Desk profiles are cfg/desk-*.kdl files. The active profile is whatever
+# file cfg/display.kdl symlinks to. Profiles declare the monitors they
+# need via comment lines:
+#
+#   // requires: <niri output long name>
+#   // optional: <free text>
+#
+# Subcommands:
+#   list            list available desk profiles
+#   current         show currently active profile (basename of display.kdl)
+#   switch <name>   apply a specific profile (name or *.kdl)
+#   cycle           apply the next profile (wraps)
+#   match [--apply] pick the profile matching connected outputs
+#   capture         print `// requires:` lines for current outputs
+#
+# Environment overrides (for tests and deploys):
+#   DESK_CFG_DIR  config dir (default ~/.config/niri/cfg)
+#   DESK_NIRI     niri binary (default niri)
+#   DESK_NOTIFY   notification command prefix (default "noctalia msg notification-show")
+
+set -euo pipefail
+
+CFG_DIR="${DESK_CFG_DIR:-$HOME/.config/niri/cfg}"
+NIRI="${DESK_NIRI:-niri}"
+NOTIFY="${DESK_NOTIFY:-noctalia msg notification-show}"
+
+usage() {
+  sed -n '2,20p' "$0" | sed 's/^# \{0,1\}//'
+}
+
+# Profile names (basenames without .kdl), sorted.
+profiles() {
+  local f
+  for f in "$CFG_DIR"/desk-*.kdl; do
+    [ -e "$f" ] || continue
+    basename "$f" .kdl
+  done | sort
+}
+
+# Active profile name, or "none".
+current() {
+  if [ -L "$CFG_DIR/display.kdl" ]; then
+    basename "$(readlink -f "$CFG_DIR/display.kdl")" .kdl
+  else
+    echo none
+  fi
+}
+
+# Connected output long names, one per line.
+outputs() {
+  "$NIRI" msg outputs 2>/dev/null | grep -oP 'Output "\K[^"]+' || true
+}
+
+# requires lines of a profile, one per line.
+requires() {
+  grep -oP '^//\s*requires:\s*\K.+' "$CFG_DIR/$1.kdl" 2>/dev/null || true
+}
+
+notify() {
+  # shellcheck disable=SC2086  # word splitting of the prefix is intended
+  $NOTIFY "Desk" "$1" 2>/dev/null || true
+}
+
+# Apply a profile: relink, validate live config, roll back on failure,
+# then reload + notify.
+apply_profile() {
+  local name="$1"
+  local file="$CFG_DIR/$name.kdl"
+  local link="$CFG_DIR/display.kdl"
+
+  [ -f "$file" ] || { echo "error: no such profile: $name" >&2; return 1; }
+
+  local old=""
+  [ -L "$link" ] && old="$(readlink "$link")"
+
+  ln -sfn "$name.kdl" "$link"
+
+  if ! "$NIRI" validate 2>/dev/null; then
+    if [ -n "$old" ]; then ln -sfn "$old" "$link"; else rm -f "$link"; fi
+    echo "error: niri validate failed; kept $( [ -n "$old" ] && basename "$old" .kdl || echo 'no' ) profile" >&2
+    return 1
+  fi
+
+  "$NIRI" msg action load-config-file 2>/dev/null || true
+  notify "switched to $name"
+  echo "switched to $name"
+}
+
+cmd_switch() {
+  local target="${1:-}"
+  [ -n "$target" ] || { echo "usage: desk.sh switch <profile>" >&2; return 1; }
+  target="${target%.kdl}"
+  apply_profile "$target"
+}
+
+cmd_match() {
+  local apply="${1:-}"
+  local connected best="" best_n=0
+  connected="$(outputs)"
+
+  local name req count
+  while IFS= read -r name; do
+    [ -n "$name" ] || continue
+    count=0
+    local ok=1
+    while IFS= read -r req; do
+      [ -n "$req" ] || continue
+      if grep -qxF "$req" <<<"$connected"; then
+        count=$((count + 1))
+      else
+        ok=0
+        break
+      fi
+    done < <(requires "$name")
+    # requires=0 profiles never match; ties go to more requires, then alphabetical
+    [ "$ok" -eq 1 ] && [ "$count" -gt 0 ] && [ "$count" -gt "$best_n" ] && { best="$name"; best_n=$count; }
+  done < <(profiles)
+
+  if [ -z "$best" ]; then
+    echo "no desk profile matches connected outputs" >&2
+    return 2
+  fi
+  if [ "$apply" = "--apply" ]; then
+    apply_profile "$best"
+  else
+    echo "$best"
+  fi
+}
+
+cmd_cycle() {
+  local list cur next
+  list="$(profiles)"
+  [ -n "$list" ] || { echo "no desk profiles found in $CFG_DIR" >&2; return 1; }
+  cur="$(current)"
+  next="$(awk -v cur="$cur" '
+    { a[NR]=$0 }
+    END { for (i=1;i<=NR;i++) if (a[i]==cur) { print a[(i%NR)+1]; exit }
+          print a[1] }' <<<"$list")"
+  apply_profile "$next"
+}
+
+cmd_capture() {
+  local n
+  n="$(outputs | wc -l)"
+  [ "$n" -gt 0 ] || { echo "error: no connected outputs (is niri running?)" >&2; return 1; }
+  echo "// paste into the profile:"
+  outputs | sed 's/^/\/\/ requires: /'
+}
+
+main() {
+  case "${1:-}" in
+    list)    profiles ;;
+    current) current ;;
+    switch)  shift; cmd_switch "$@" ;;
+    cycle)   cmd_cycle ;;
+    match)   shift; cmd_match "${1:-}" ;;
+    capture) cmd_capture ;;
+    -h|--help) usage ;;
+    *)       usage >&2; exit 1 ;;
+  esac
+}
+
+main "$@"