Update CLI for control surface mode

[joaodotwork]

Description

Extend the CLI to support the new control surface mode alongside the existing video bridge mode.

Tasks

• Add --mode flag: video (default, existing behavior) or control (new parameter display)
• Add --vdmx-host and --vdmx-port options (default: 127.0.0.1:1234)
• Add --osc-listen-port option (default: 9001)
• Add --oscquery-url option (fallback when Bonjour discovery fails)
• Add --sensitivity for encoder acceleration factor
• Update --help with mode descriptions and examples
• Update README with control surface mode documentation

Acceptance Criteria

• push2-bridge --mode control starts the control surface
• push2-bridge (no args) still starts the video bridge as before
• All new options have sensible defaults
• README documents the full control surface workflow (VDMX setup → bridge → usage)

Technical Notes

# Video bridge (existing)
push2-bridge

# Control surface mode
push2-bridge --mode control

# With custom VDMX ports
push2-bridge --mode control --vdmx-port 5678 --osc-listen-port 9002