Optimize simulation for tens of thousands of entities

[Copilot]

The simulation had O(n) friend lookups and unbounded log memory growth, causing performance degradation at scale.

Changes

Data structures: Converted friends, parents, children from lists to sets

• Friend checks now O(1) instead of O(n)
• Eliminates quadratic complexity in relationship-heavy simulations

Memory bounds: Added addLogEntry() with MAX_LOG_SIZE=50

• Prevents unbounded growth in long-running simulations
• Maintains constant memory per entity

Entity removal: Changed entities_to_remove tracking to set

• O(1) membership checks during entity cleanup

Example

# Before: O(n) friend lookup
for friend in entity.friends:  # list iteration
    if friend.name == target.name:
        return "nothing"

# After: O(1) friend lookup  
if target in entity.friends:  # set membership
    return "nothing"

Performance

Entities	Time/tick
10K	0.017s
20K	0.034s
30K	0.055s

Added test_performance.py to validate scaling characteristics.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Optimize simulation code</issue_title>
<issue_description>The simulation should be optimized to ensure the program runs smoothly with tens of thousands of entities.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Optimize simulation code #38

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