Add environmental observations (terrain, cues, weather, stamina)

[justinmadison]

Summary

Enrich the observation payload with environmental information that requires the LLM to interpret ambiguous signals and make inferences.

Motivation

Current observations are purely factual: exact positions of visible resources and hazards. Real-world foraging requires interpreting partial information. Adding environmental observations tests the LLM's ability to reason under uncertainty.

Implementation Details

Terrain Types

• Mud zones: Slow agent movement to 50% speed. Visible in observations as terrain type.
• Hills: Block line-of-sight but allow movement. Agent on a hill gets extended perception range.
• Water: Impassable. Forces routing decisions.
• Implementation: Add terrain layer to the scene (could use Area3D zones or a grid-based terrain map)

Sensory Cues (Directional Hints)

• "You hear running water to the north" — hints at water boundary (impassable)
• "You see smoke rising to the east" — could be fire hazard OR a useful campfire
• "You smell something sweet to the south" — hints at apple cluster
• Implementation: Add sensory_cues array to observation payload. Generate cues based on distance/direction to off-screen objects.

Weather System

• Rain: Extinguishes fire hazards but creates mud zones. Reduces perception radius slightly.
• Night cycle: Reduces perception radius by 50%. Makes exploration tools even more critical.
• Wind: Affects fire spread direction
• Implementation: Weather state machine in scene controller, affects perception_radius and hazard behavior per tick.

Stamina System

• Agent has stamina that depletes with movement (proportional to distance traveled)
• Running out of stamina forces the agent to rest (idle for N ticks)
• Moving through mud costs double stamina
• Forces the agent to plan efficient routes instead of wandering randomly
• Implementation: Add stamina and max_stamina to agent state, stamina_cost_per_meter constant

Observation Payload Additions

{
  "terrain_at_position": "grass|mud|hill",
  "sensory_cues": ["You smell something sweet to the south"],
  "weather": "clear|rain|night",
  "stamina": 75,
  "max_stamina": 100
}

Impact on RAG Memory

• "Mud zone between (3,0,2) and (7,0,5) — costs double stamina, avoid unless necessary"
• "When it rains, fire at (1,0,1) goes out — safe window to cross"
• "Sweet smell from south usually means apples near (-5,0,8)"
• Interpreting and remembering sensory cues across episodes is a compelling use of semantic memory

Acceptance Criteria

• At least 2 terrain types implemented and placed in scene
• Sensory cues generated based on nearby off-screen objects
• Weather system with at least 2 states that affect gameplay
• Stamina system limits unlimited wandering
• Observation payload includes all new fields
• Decision prompt updated to explain environmental signals to the LLM