fix: cache vehicle cargo recharge targets

[scarf005]

Purpose of change (The Why)

Vehicle recharge processing was rescanning cargo contents every turn in item-heavy vehicles, and solar-equipped battery buses were also paying repeated battery-part scans in vehicle power paths. Together they made crafting, reading, and nearby vehicle turns stutter again around large mobile bases.

Likely BN regression sources:

• #8252 feat!: Map Data Overhaul; dynamic reality bubble, chunk loader, multi-dimension, and more
• #8439 fix: activity bubble resize works w/ crafting

Describe the solution (The How)

• cache vehicle cargo recharge candidates behind dirty invalidation instead of rescanning all cargo every tick
• keep a dedicated battery part index and replace multimap-based battery balancing with percentage buckets in charge/discharge paths
• add regression benchmarks for cargo-heavy crafting, cargo recharge, and solar+battery vehicle power scenarios

Testing

• cmake --build --preset linux-full --target cata_test-tiles
• ./out/build/linux-full/tests/cata_test-tiles "[vehicle][power]"
• ./out/build/linux-full/tests/cata_test-tiles "[grids][vehicle]"
• ./out/build/linux-full/tests/cata_test-tiles "[benchmark][vehicle]" --benchmark-samples 1 --benchmark-resamples 0

Scenario	Before	After	Faster
process_items with recharge station and 8196 cargo items	412.318 us	6.401 us	64.4x
vehicle idle with 64 solar panels and 512 storage batteries	166.974 us	115.568 us	1.44x
vehicle solar backfill with 64 panels and 512 storage batteries	157.827 us	124.385 us	1.27x

Additional context

Reproduction reports:

• https://m.dcinside.com/board/rlike/512733
• https://m.dcinside.com/board/rlike/515377
• https://m.dcinside.com/board/rlike/515402
• https://m.dcinside.com/board/rlike/515446

Checklist

Mandatory

• I wrote the PR title in conventional commit format.
• I ran the code formatter.
• I linked any relevant issues using github keyword syntax like closes #1234 in Summary of the PR so it can be closed automatically.
• I've committed my changes to new branch that isn't main so it won't cause conflict when updating main branch later.

^{PR opened by gpt-5.4 high on opencode}