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/ltp305-python/REFERENCE.md

@@ -0,0 +1,128 @@
+# Pimoroni LTP305 LED Matrices Breakout <!-- omit in toc -->
+
+The LTP305 breakout includes two LTP305 displays and an i2c dual matrix driver to drive them.
+
+- [Getting Started](#getting-started)
+  - [Pre-requisites](#pre-requisites)
+    - [Python 3 & pip](#python-3--pip)
+    - [Enabling i2c](#enabling-i2c)
+  - [Installing the library](#installing-the-library)
+- [Reference](#reference)
+  - [set_pixel](#set_pixel)
+  - [set_decimal](#set_decimal)
+  - [set_character](#set_character)
+  - [set_image](#set_image)
+  - [get_shape](#get_shape)
+  - [clear](#clear)
+  - [show](#show)
+
+## Getting Started
+
+You'll need to install the LTP305 software library and enable i2c on your Raspberry Pi.
+
+### Pre-requisites
+
+#### Python 3 & pip
+
+You should use Python 3, which may need installing on your Pi:
+
+```
+sudo apt update
+sudo apt install python3 python3-pip
+```
+
+#### Enabling i2c
+
+You can use `sudo raspi-config` on the command line, the GUI Raspberry Pi Configuration app from the Pi desktop menu, or use the following command to enable i2c:
+
+```
+sudo raspi-config nonint do_i2c 0
+```
+
+### Installing the library
+
+```python
+python3 -m pip install ltp305
+```
+
+## Reference
+
+In all cases you'll want to create an instance of the LTP305 class with the appropriate i2c address for your device.
+
+The following addresses are available:
+
+* `0x61` - Default address
+* `0x62` - Solder bridge applied to Addr+1
+* `0x63` - Cut Addr+2
+
+```python
+from ltp305 import LTP305
+display = LTP305(address=0x61)
+```
+
+### set_pixel
+
+Set a single pixel. Treats both matrices as a single display that's 10 pixels wide and 7 pixels high.
+
+```python
+display.set_pixel(0, 0, 1)
+display.show()
+```
+
+### set_decimal
+
+Set the decimal dot on one or both matrix displays:
+
+```python
+display.set_decimal(left=True, right=False)  # Just the left
+display.set_decimal(left=False, right=True)  # Just the right
+display.set_decimal(left=True, right=True)   # Both
+display.show()
+```
+
+### set_character
+
+The library includes a font with a range of ASCII and Unicode characters, each matrix can display a single character.
+
+```python
+display.set_character(0, "a")
+display.set_character(5, "b")
+display.show()
+```
+
+### set_image
+
+Set a 1-bit PIL image to the display.
+
+```python
+from PIL import Image, ImageDraw
+image = Image.new("1", display.get_shape())
+draw = ImageDraw.draw(image)
+draw.rectangle((0, 0, 4, 6), 1)
+display.set_image(image)
+display.show()
+```
+
+### get_shape
+
+Return the width and height of the display:
+
+```python
+width, height = display.get_shape()
+```
+
+### clear
+
+Clear the display. Sets all pixels in the buffer to 0 (off). You must call `show()` to update the display.
+
+```python
+display.clear()
+```
+
+### show
+
+Once you've finished setting pixels or drawing characters into the buffer, you must call `show` to update the matrices with the buffer:
+
+```python
+display.show()
+```