Migrate WiFi and Power/Display/Quiet Hours menus; bump to v2.3.0

By far the riskiest menus migrated so far. Both can affect real system
state outside config.json in ways that are hard to reverse: WiFi
rewrites live netplan config and, over SSH, can disconnect the very
session configuring it; power scheduling can shut the physical machine
down and wake it via RTC.

- lib/config.sh: new $SYSTEMD_DIR/$CRON_D_DIR/$BIN_DIR/$NETPLAN_DIR,
  same `: "${VAR:=default}"` pattern as $KIOSK_DIR. Nothing under
  menus/ hardcodes /etc/systemd/system, /etc/cron.d, /usr/local/bin, or
  /etc/netplan directly, so every test in this change points them at
  scratch space instead of ever touching this sandbox's real systemd
  units, cron, or network config.
- lib/menu.sh: ported get_ip_address (also fixing its "No IP" fallback,
  which never actually fired before - `hostname -I | awk` always exits
  0 even on empty output).
- menus/wifi.sh: apply_wifi_config split out from wifi_menu specifically
  so tests can drive the netplan-writing logic without needing real
  scan hardware. Preserves the legacy netplan backup, 60s SSH watchdog,
  and restore-on-failure behavior exactly.
- menus/power_schedule.sh: power schedule (+ RTC wake), display
  schedule, quiet hours, and an Electron reload timer (with its own
  nested run_menu, mirroring the legacy configured/not-configured
  dispatch), plus remove-all. Deliberately excludes the legacy
  dispatcher's "Test schedules & system" - a shared diagnostics submenu
  (audio/network/keyboard tests) that isn't specific to scheduling and
  belongs with a future Advanced/Diagnostics migration instead.

Bugs found and fixed along the way, none papered over:
- The legacy dispatcher refused to open "Configure power schedule" at
  all without RTC hardware, even though shutdown-only mode never needed
  RTC. Now always available.
- None of the six HH:MM prompts across these menus (shutdown, wake,
  display off/on, quiet start/end, custom Electron reload time) were
  validated before - plain `read`, no format check. All now go through
  ask_time.
- set -e safety (same class as the v2.1.0 run_menu fix), three more
  instances: `ls *.yaml` when no netplan file exists still fails under
  pipefail even with stderr silenced (masked in practice by cloud-init
  usually leaving a file behind); the restore-and-reapply `netplan
  apply` after an initial failure was a bare unguarded statement; and
  `systemctl enable`/`start` after writing each of the four timer pairs
  was unguarded too - caught only by testing in an environment without
  a live systemd, but a real enable/start failure on actual hardware
  (bad unit, daemon-reload skipped, ...) would hit the exact same crash.
  Added a shared enable_and_start_timers() helper used at all four call
  sites; all now report a clear warning and return to the menu instead
  of taking the session down.

Testing discipline for this round, given the risk:
- No automated test calls the real netplan/nmcli/iw/wpa_cli/systemctl -
  confirmed no WiFi tools or `wl*` interface exist in this sandbox, so
  wifi_menu's own tools-check safely short-circuits before touching
  anything; apply_wifi_config's actual YAML/backup/failure-recovery
  logic is tested with sudo/netplan/get_ip_address stubbed instead.
- One stubbing pitfall caught and fixed in the test itself: `nohup sudo
  bash "$watchdog" ... &` execs nohup as a real external binary, which
  then execs the real sudo - a bash function stub named `sudo` does NOT
  intercept that, only stubbing `nohup` itself does. Verified via pgrep
  that no real watchdog process or `sleep 60` was ever spawned.
- power_schedule.sh tested with SYSTEMD_DIR/CRON_D_DIR/BIN_DIR pointed
  at scratch dirs and only `sudo systemctl` stubbed (tee/rm/chmod/cp
  left real, since they only ever touch scratch paths): full lifecycle
  for all four schedule types plus remove-all, the RTC-available branch
  (including the wake-time-before-shutdown-time hour/day wraparound
  arithmetic) via a stubbed rtc_wake_available, and the new
  enable_and_start_timers failure path via a stub that fails `enable`
  specifically.
- End-to-end: ran the real install.sh as a genuine non-root, non-
  "kiosk" user for both menus. WiFi correctly short-circuits on missing
  tools without crashing. Power/Display/Quiet Hours (SYSTEMD_DIR/
  CRON_D_DIR/BIN_DIR redirected to scratch space) configured all four
  schedule types in sequence including the nested Electron Reload menu,
  survived four consecutive real "systemctl enable/start failed"
  warnings (this container has no live systemd) without the session
  dying, then removed everything - confirmed the scratch dirs ended up
  empty and config.json was never touched (correctly out of scope for
  this menu).

Readme.md

@@ -1,6 +1,6 @@
 # Ubuntu Based Kiosk
 
-**Current Version:** 2.2.0 (check script header for latest version)
+**Current Version:** 2.3.0 (check script header for latest version)
 **Built with Claude Sonnet 4.6 AI assistance**
 **License:** GPL v3 - Keep derivatives open source
 **Repository:** https://github.com/outis1one/ubuntu-based-kiosk/
@@ -1194,6 +1194,14 @@ terminal menu and the web UI, so they can't drift apart).
   change password, inactivity timeout, daily lock time, boot password.
   The password is SHA-256 hashed before it's ever written to disk, same
   as the legacy menu — never stored as plaintext.
+- `menus/wifi.sh` — **WiFi**: the riskiest menu so far — rewrites live
+  netplan config and, over SSH, can disconnect the session configuring
+  it. Preserves the legacy menu's netplan backup, 60-second SSH
+  watchdog, and restore-on-failure exactly.
+- `menus/power_schedule.sh` — **Power/Display/Quiet Hours**: scheduled
+  shutdown (+ RTC wake where available), display on/off, quiet-hours
+  audio muting, and an Electron reload timer, each as systemd timers.
+  Can power the physical machine off and on a schedule.
 - `install.sh` — entry point for the modular tool. Run it against an
   *already-installed* kiosk:
   ```bash
@@ -1205,9 +1213,8 @@ terminal menu and the web UI, so they can't drift apart).
 **Honest status:** this does not yet replace first-time installation, or
 most of the old installer. `ubuntu-based-kiosk.sh` is still ~12,000
 lines and still contains its own unremoved, unmodified copies of every
-menu above (plus WiFi, Power/Display/Quiet Hours, Upgrade, Reinstall,
-Uninstall, all Addons, and all of Advanced — none of that has moved
-yet). Both copies coexist deliberately: the old ones stay until enough
+menu above (plus Upgrade, Reinstall, Uninstall, all Addons, and all of
+Advanced — none of that has moved yet). Both copies coexist deliberately: the old ones stay until enough
 of Core Settings/Addons/Advanced is migrated to
 retire them in one pass, rather than leaving the legacy menu half-wired.
 Migration continues one `menus/*.sh` file at a time; first-time
@@ -1218,9 +1225,16 @@ at all.
 
 ## Project Status & Future Plans
 
-**Current Version:** 2.2.0
+**Current Version:** 2.3.0
 
-**Recent Updates (v2.2.0):**
+**Recent Updates (v2.3.0):**
+- **WiFi and Power/Display/Quiet Hours migrated** — by far the riskiest menus tackled so far. WiFi rewrites live netplan config and, over SSH, can disconnect the session configuring it; power scheduling can shut the physical machine down and wake it via RTC. Every legacy safety mechanism is preserved exactly: netplan backup, 60-second SSH watchdog, restore-on-failure for WiFi; RTC availability detection for power scheduling.
+- **Bug fix:** the legacy menu refused to open "Configure power schedule" at all without RTC hardware, even though shutdown-only scheduling never needed it.
+- **Bug fix:** none of the six HH:MM time prompts across these menus were format-validated before — a typo silently produced a broken schedule. All now go through the same `ask_time` validator as everywhere else.
+- **Bug fix (set -e safety):** several more bare statements whose failure would have killed the entire session — `ls *.yaml` with no netplan file present, the backup-restore reapply after a failed `netplan apply`, and `systemctl enable`/`start` after writing each timer pair. The last was only caught by testing without a live systemd; a real failure on actual hardware would have hit the same crash. All now report a warning and return to the menu.
+- Deliberately **not** migrated: the legacy "Test schedules & system" option, which leads into a shared diagnostics submenu (audio/network/keyboard tests) unrelated to scheduling — that belongs with a future Advanced/Diagnostics pass.
+
+**Previous (v2.2.0):**
 - **Fifth menu migrated:** Password Protection & Lockout (`menus/lockout.sh`) — enable/disable, change password, inactivity timeout, daily lock time, boot password. The password is SHA-256 hashed before it's ever written to `config.json` (matching the Electron app's own comparison logic) — verified never stored as plaintext.
 - **Bug fix:** `lib/menu.sh` was missing `ask_time`/`validate_time` entirely — caught by testing this menu before it shipped; "set a daily lock time" would otherwise have failed for every user. Ported from the legacy script.
 - **Refactor:** promoted the ON/OFF toggle-label helper out of `menus/display.sh` into a shared `onoff()` in `lib/menu.sh`, so `menus/lockout.sh` doesn't need to depend on another menu file — menus only ever depend on `lib/`.