Add arrow display on mobile when earth is selected

[wannerdev]

Description

Adds a directional arrow indicator on mobile devices that shows the launch direction from Earth to the touch position, similar to the mouse cursor arrow on desktop.

Changes

• Created new launch_arrow module in effects
• Implemented draw_launch_arrow system
• Shows orange/amber arrow from Earth (LaunchPad) to touch position
• Only displays when launch is armed (earth is selected)
• Arrow includes directional head (V-shaped tip)
• Updates in real-time as finger moves across screen
• Converts touch screen position to world coordinates
• Integrated into effects plugin system

Visual Details

• Color: Orange/amber (RGB: 1.0, 0.6, 0.2) with 80% opacity
• Length: 15.0 units from Earth center
• Arrow Head: V-shaped tip with 3.0 unit size
• Style: Matches game's retro orange/amber theme
• Visibility: Only when LaunchArmed is true

Behavior

• Shows: When earth is tapped/selected (LaunchArmed = true)
• Hides: When launch is executed or earth is deselected
• Updates: Every frame as touch position changes
• Direction: Points from Earth center toward touch location
• Mobile-specific: Only responds to touch input

Benefits

• Provides same directional feedback as desktop mouse cursor
• Helps mobile users aim their satellite launches accurately
• Makes launch direction clear before releasing
• Improves mobile UX parity with desktop
• Enhances launch precision on touch devices
• Visual consistency with desktop experience

Technical Implementation

• Queries LaunchArmed resource to check if earth is selected
• Gets Earth position from LaunchPad transform
• Reads touch input events for current finger position
• Converts screen coordinates to world coordinates
• Calculates direction vector and normalizes it
• Draws arrow shaft and head using gizmos
• Uses perpendicular vector for arrow head geometry

Desktop vs Mobile

• Desktop: Mouse cursor shows direction naturally
• Mobile: This arrow provides equivalent visual feedback
• Parity: Both platforms now have clear directional indicators
• Consistency: Same visual language across platforms

Performance

• Lightweight: Only draws when launch is armed
• Efficient: Uses gizmos (no sprites/meshes)
• Minimal: Simple line rendering (3 lines total)
• Real-time: Updates every frame for smooth tracking

Testing

• Tap Earth on mobile device to arm launch
• Verify orange arrow appears from Earth
• Move finger and verify arrow follows touch position
• Check arrow head points in correct direction
• Release touch and verify arrow disappears
• Confirm arrow matches game's color theme

Related Issue

Fixes: Android/Mobile Feedback - When having a mouse there is an Arrow, display this on the mobile as well when earth is selected (mobile)