Update README to reflect current runtime and install behavior

README.md

@@ -11,20 +11,27 @@ Headless Raspberry Pi Zero W project:
 ## Current State
 
 Current implementation status:
-- Boot flow restores system time from RTC (`hwclock -s`) before starting logging.
-- If WLAN + internet is unavailable, AP fallback starts on `wlan0`:
+- Boot flow restores system time from RTC (`hwclock -s`) before starting services.
+- RTC device auto-detection checks: configured device, `/dev/rtc`, `/dev/rtc0`, `/dev/rtc1`.
+- If WLAN is disconnected for ~60s, AP fallback starts on `wlan0`:
   - SSID: `serial`
   - Password: `serialserial`
   - AP IP: `192.168.4.1/24`
   - DHCP range: `192.168.4.10` to `192.168.4.200`
 - Web portal is available on port `80`:
-  - `/` WiFi scan + connect UI
+  - `/` WiFi scan + connect UI + system actions (reboot/shutdown)
   - `/serial` live serial console (SSE via `/events/serial`)
+  - `/api/status` polling is reduced/throttled (15s) for Pi Zero W performance
 - ESP32 serial bridge:
   - Auto-detects `/dev/ttyUSB*`, `/dev/ttyACM*`, `/dev/serial/by-id/*`
   - Reconnects automatically on unplug/replug
   - Daily log rollover at midnight with datetime filename
+  - No log file is created while no serial device is connected
 - Once internet is available, NTP sync runs and writes corrected time back to RTC (`hwclock -w`).
+- After boot is ready, power/activity LED is set to 1 Hz blink (`timer`, 500ms on / 500ms off), if LED sysfs control is available.
+
+Note:
+- Reboot/shutdown actions in the web UI currently have no authentication. Restrict access to trusted networks only.
 
 Runtime check commands:
 ```bash
@@ -62,7 +69,7 @@ sudo reboot
 
 Verify:
 ```bash
-ls -l /dev/rtc0
+ls -l /dev/rtc*
 sudo i2cdetect -y 1
 sudo hwclock -r
 ```
@@ -74,7 +81,12 @@ chmod +x install.sh
 sudo ./install.sh
 ```
 
-Then reboot:
+Installer behavior:
+- First run: full install (apt packages, venv, pip deps, configs, services).
+- Re-run/update: fast path, skips apt and pip when not needed.
+- `pip install` runs only when `requirements.txt` hash changed (or venv missing).
+
+Optional reboot after first install or low-level config changes:
 
 ```bash
 sudo reboot