feat(uno-q): wire i2c_scan into the relay, allowlist, and modulino skill

- matrix-relay/relay.py: handle the `i2c` command → Bridge.call("i2c_scan").
- config.template: allow + auto-approve i2c_scan on the default risk profile.
- modulino skill: point "confirm a module is present" at i2c_scan (MCU Qwiic
  bus) instead of the Linux i2cdetect.

Completes the container-native path: the three canned prompts (list I2C /
matrix pattern / scroll text) all run through the RouterBridge responder —
no /dev/i2c, no flash — so they work in the App Lab container node.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

deploy/uno-q/skills/modulino/SKILL.md

@@ -7,7 +7,7 @@ description: Plug-and-play Modulino sensors/actuators for the Arduino Uno Q —
 
 Modulinos are Arduino's Qwiic (I²C) plug-and-play modules. Chain them into the
 Uno Q's **Qwiic connector (I2C4)** — no soldering, no pull-ups to add. Use the
-`Modulino` Arduino library on the MCU, or scan the bus with the `i2cdetect` tool.
+`Modulino` Arduino library on the MCU, or scan the bus with the `i2c_scan` tool.
 
 ## Default I²C addresses
 
@@ -32,7 +32,7 @@ void loop()  { int v = knob.get(); /* ... */ }
 
 ## Tips
 
-- Confirm a module is present with `i2cdetect` (scan the Qwiic bus) — the address
+- Confirm a module is present with `i2c_scan` (scan the Qwiic/I2C bus on the MCU) — the address
   should match the table above.
 - Qwiic is 3.3 V, like the rest of the Arduino headers.
 - The Movement Modulino (0x6A) is an IMU — handy for the workshop's sense loop.