Act as an expert Electronics Hardware and PCB Design Engineer. I need to design a 2-layer custom color grading console called "ROUND CONSOLE". Please generate the complete schematic, component placement guidelines, and routing paths based on the exact hardware profile and connection map provided below.

### 1. COMPONENT PROFILE & POWER RATINGS
- MCU: Raspberry Pi Pico H (RP2040 Chip, 3.3V logic). Powered via standard 5V USB-C.
- Input Voltage from USB: 5V @ 1A to 2A max.
- System Logic Voltage: 3.3V generated by the onboard regulator of Raspberry Pi Pico.
- Trackball Sensors: 3x PMW3360 Optical Sensor Modules (SPI Interface, Max current ~30mA each, operates at 3.3V).
- I/O Expander IC: 2x MCP23017-E/SP (DIP-28 Package, operates at 3.3V, used for key matrix).
- Shift Register IC: 2x 74HC165 (DIP-16 Package, operates at 3.3V).
- Display: 1x SSD1306 0.96-inch OLED Module (I2C Interface, 128x64 resolution, operates at 3.3V).
- Encoders: 6x KY-040 Incremental Rotary Encoders (3.3V signal pull-up).
- Keyswitches: 25x Gateron Brown Mechanical Switches.
- Diodes: 30x 1N4148 Fast Switching Diodes (Through-hole DO-35 package, 500mW / 0.5W power rating).
- Resistors: 10x 10k Ohm Resistors (Through-hole axial, 0.25W / 0.125W rating for I2C pull-ups).

### 2. PIN-TO-PIN WIRE CONNECTION MAP

#### A. Power Rails & Decoupling
- Connect Pico Pin 36 (3V3_OUT) to the VCC/VDD pins of: both MCP23017 chips, both 74HC165 chips, SSD1306 OLED, and all 3x PMW3360 sensors.
- Connect Pico Pin 38 (GND) to the GND/VSS pins of: both MCP23017 chips, both 74HC165 chips, SSD1306 OLED, and all 3x PMW3360 sensors.
- Place a 0.1uF ceramic decoupling capacitor close to the VDD pins of each IC.

#### B. High-Speed SPI Bus (Trackball Sensors Tracking)
Route the 3x PMW3360 sensors in a parallel SPI configuration:
- Connect MISO pins of all 3 sensors together ➡️ Pico Pin 21 (GP16 / SPI0 RX)
- Connect MOSI pins of all 3 sensors together ➡️ Pico Pin 25 (GP19 / SPI0 TX)
- Connect SCK pins of all 3 sensors together  ➡️ Pico Pin 24 (GP18 / SPI0 SCK)
Configure dedicated Chip Select (CS) lines:
- Connect Lift Sensor CS ➡️ Pico Pin 22 (GP17)
- Connect Gamma Sensor CS ➡️ Pico Pin 26 (GP20)
- Connect Gain Sensor CS ➡️ Pico Pin 27 (GP21)

#### C. I2C Bus (OLED Display & I/O Expander)
Route the I2C lines to form a shared bus:
- Connect SDA pins of OLED and MCP23017 (Pin 13) together ➡️ Pico Pin 6 (GP4 / I2C0 SDA)
- Connect SCL pins of OLED and MCP23017 (Pin 12) together ➡️ Pico Pin 7 (GP5 / I2C0 SCL)
- CRITICAL: Add 10k Ohm pull-up resistors from the SDA line to 3.3V, and from the SCL line to 3.3V.

#### D. 5x5 Matrix Keyboard Routing
- Arrange the 25 Gateron Brown switches into a 5 Rows by 5 Columns matrix.
- Place a 1N4148 diode (0.5W) in series with each switch to prevent ghosting.
- Route Rows 1, 2, 3, 4, 5 ➡️ MCP23017 Pins 1, 2, 3, 4, 5 (GPA0 to GPA4).
- Route Columns 1, 2, 3, 4, 5 ➡️ MCP23017 Pins 21, 22, 23, 24, 25 (GPB0 to GPB4).

#### E. Primary Dials (KY-040 Encoders)
Route the CLK and DT pins of the 6 encoders directly to the remaining GPIO pins on the Raspberry Pi Pico:
- Knob 1 (Contrast): CLK ➡️ GP6 (Pin 9), DT ➡️ GP7 (Pin 10)
- Knob 2 (Pivot): CLK ➡️ GP8 (Pin 11), DT ➡️ GP9 (Pin 12)
- Knob 3 (Saturation): CLK ➡️ GP10 (Pin 14), DT ➡️ GP11 (Pin 15)
- Knob 4 (Hue): CLK ➡️ GP12 (Pin 16), DT ➡️ GP13 (Pin 17)
- Knob 5 (Lum Mix): CLK ➡️ GP14 (Pin 19), DT ➡️ GP15 (Pin 20)
- Knob 6 (Tint): CLK ➡️ GP22 (Pin 29), DT ➡️ GP26 (Pin 31)

### 3. PCB ROUTING & MANUFACTURING RULES
- Set PCB Trace Width for Power lines (3.3V and GND) to 0.5mm minimum to ensure stable power delivery.
- Set PCB Trace Width for Data lines (SPI and I2C) to 0.25 switch traces.
- Keep SPI differential pairs/lines routed closely together to reduce clock jitter.
- Generate a large Ground Pour / Ground Plane on both the top and bottom copper layers for noise mitigation.
- Keep the overall board shape rectangular but with smooth rounded corners suitable for a custom 3D-printed enclosure.

Please render the schematic logic and auto-route the traces according to these structural inputs.