Initial backup of LTP-305G matrix clock setup on matrixpi

Captures everything needed to redeploy the two-display clock (hour on I2C
0x61, minute on I2C 0x63) on a fresh Pi:

- Both systemd units (matrix0x61.service, matrix0x63.service)
- Deployed Pimoroni script tree, including the local %I (12-hour) clock
  customization
- Vendored upstream sources (ltp305-python, breakout-garden) so restore is
  fully offline-capable
- Boot config snippet enabling I2C
- install.sh that wires it all back up idempotently
- Inventory doc cross-referencing every live-system path

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

vendor/breakout-garden/examples/nightlight/nightlight.py

@@ -0,0 +1,103 @@
+#!/usr/bin/env python3
+
+import time
+
+from ltr559 import LTR559
+from rgbmatrix5x5 import RGBMatrix5x5
+
+print("""This Pimoroni Breakout Garden example requires an
+LTR-559 Light and Proximity Breakout and a 5x5 RGB Matrix Breakout.
+This example creates a little nightlight that can be toggled on or
+off by tapping the proximity sensor with your finger, or triggered
+automatically when it's dark.
+
+Press Ctrl+C to exit.
+""")
+
+# Set up the LTR-559 sensor
+
+ltr559 = LTR559()
+
+# Set up the 5x5 RGB matrix
+rgbmatrix5x5 = RGBMatrix5x5()
+rgbmatrix5x5.set_clear_on_exit()
+rgbmatrix5x5.set_brightness(0.8)
+
+# Initial variables to keep track of state of light
+state = False
+last_state = False
+toggled = False
+
+light_threshold = 100  # Low-light trigger level
+prox_threshold = 1000  # Proximity trigger level
+colour = (255, 165, 0)  # Orange-ish
+
+
+# Function to toggle the RGB matrix on or off depending on state
+def toggle_matrix():
+    global state, last_state
+
+    if state is True and last_state is False:
+        rgbmatrix5x5.set_all(*colour)
+        rgbmatrix5x5.show()
+    elif state is False and last_state is True:
+        rgbmatrix5x5.clear()
+        rgbmatrix5x5.show()
+
+    last_state = state
+
+
+# Read the sensor once, as the first values are always squiffy
+ltr559.update_sensor()
+lux = ltr559.get_lux()
+prox =ltr559. get_proximity()
+time.sleep(1)
+
+try:
+    while True:
+        # Read the light and proximity sensor
+        ltr559.update_sensor()
+        lux = ltr559.get_lux()
+        prox = ltr559.get_proximity()
+
+        # If it's dark and the light isn't toggled on, turn on
+        if lux < light_threshold and not toggled:
+            state = True
+            if state != last_state:
+                print("It's dark! Turning light ON")
+            toggle_matrix()
+
+        # If it's light and the light isn't on, turn off
+        elif lux >= light_threshold and not toggled:
+            state = False
+            if state != last_state:
+                print("It's light! Turning light OFF")
+            toggle_matrix()
+
+        # If there's a tap on the sensor
+        if prox > prox_threshold:
+            # Toggle it off if it's currently on
+            if toggled:
+                state = False
+                toggled = False
+                if state != last_state:
+                    print("Toggling light OFF")
+                toggle_matrix()
+            # Toggle it on if it's currently off
+            else:
+                state = True
+                toggled = True
+                if state != last_state:
+                    print("Toggling light ON")
+                toggle_matrix()
+            # Wait a short while to prevent the on/off switch
+            # from immediately re-triggering
+            time.sleep(0.5)
+
+        elif prox < prox_threshold and lux >= light_threshold:
+            state = False
+
+        time.sleep(0.05)
+
+except KeyboardInterrupt:
+    pass