feat: Support installing built-in AGENT files and skills during picoclaw onboard

workspace/skills/hardware/SKILL.md

@@ -0,0 +1,64 @@
+---
+name: hardware
+description: Read and control I2C and SPI peripherals on Sipeed boards (LicheeRV Nano, MaixCAM, NanoKVM).
+homepage: https://wiki.sipeed.com/hardware/en/lichee/RV_Nano/1_intro.html
+metadata: {"nanobot":{"emoji":"🔧","requires":{"tools":["i2c","spi"]}}}
+---
+
+# Hardware (I2C / SPI)
+
+Use the `i2c` and `spi` tools to interact with sensors, displays, and other peripherals connected to the board.
+
+## Quick Start
+
+```
+# 1. Find available buses
+i2c detect
+
+# 2. Scan for connected devices
+i2c scan  (bus: "1")
+
+# 3. Read from a sensor (e.g. AHT20 temperature/humidity)
+i2c read  (bus: "1", address: 0x38, register: 0xAC, length: 6)
+
+# 4. SPI devices
+spi list
+spi read  (device: "2.0", length: 4)
+```
+
+## Before You Start — Pinmux Setup
+
+Most I2C/SPI pins are shared with WiFi on Sipeed boards. You must configure pinmux before use.
+
+See `references/board-pinout.md` for board-specific commands.
+
+**Common steps:**
+1. Stop WiFi if using shared pins: `/etc/init.d/S30wifi stop`
+2. Load i2c-dev module: `modprobe i2c-dev`
+3. Configure pinmux with `devmem` (board-specific)
+4. Verify with `i2c detect` and `i2c scan`
+
+## Safety
+
+- **Write operations** require `confirm: true` — always confirm with the user first
+- I2C addresses are validated to 7-bit range (0x03-0x77)
+- SPI modes are validated (0-3 only)
+- Maximum per-transaction: 256 bytes (I2C), 4096 bytes (SPI)
+
+## Common Devices
+
+See `references/common-devices.md` for register maps and usage of popular sensors:
+AHT20, BME280, SSD1306 OLED, MPU6050 IMU, DS3231 RTC, INA219 power monitor, PCA9685 PWM, and more.
+
+## Troubleshooting
+
+| Problem | Solution |
+|---------|----------|
+| No I2C buses found | `modprobe i2c-dev` and check device tree |
+| Permission denied | Run as root or add user to `i2c` group |
+| No devices on scan | Check wiring, pull-up resistors (4.7k typical), and pinmux |
+| Bus number changed | I2C adapter numbers can shift between boots; use `i2c detect` to find current assignment |
+| WiFi stopped working | I2C-1/SPI-2 share pins with WiFi SDIO; can't use both simultaneously |
+| `devmem` not found | Download separately or use `busybox devmem` |
+| SPI transfer returns all zeros | Check MISO wiring and device power |
+| SPI transfer returns all 0xFF | Device not responding; check CS pin and clock polarity (mode) |