Reduce perception radius to force exploration

[justinmadison]

Summary

Reduce the agent's perception_radius from 50.0 (covers entire 50x50m map) to 8-12 units to force meaningful exploration decisions.

Motivation

Currently in scripts/base_scene_controller.gd, perception_radius = 50.0 allows the agent to see the entire map at once. This trivializes navigation — the agent always knows where every resource and hazard is. Reducing it forces the agent to:

• Decide where to explore rather than just what to collect
• Use plan_path, explore_direction, and get_exploration_status tools (currently unused)
• Remember previously seen resource/hazard locations (drives RAG memory integration)

Implementation Details

• Change perception_radius from 50.0 to 10.0 (adjustable via export var) in scripts/base_scene_controller.gd
• Verify line-of-sight raycasting still works at reduced range
• Update the starter agent to use exploration tools (plan_path, explore_direction, get_exploration_status)
• Update system/decision prompts to instruct the LLM about limited visibility
• Consider adding a perception_radius field to observation payload so the LLM knows its range

Impact on RAG Memory

This is the #1 driver for making long-term memory essential. With limited perception, the agent needs to remember:

• Where it previously saw resources
• Which areas it has already explored
• Where hazards were located

Acceptance Criteria

• perception_radius reduced to ~10.0 (configurable)
• Agent cannot see resources/hazards beyond the radius
• Starter agent updated to use exploration tools
• Decision prompt updated to reflect limited visibility
• Observation payload includes perception range info