feat: add deterministic input replay

[scarf005]

Purpose of change (The Why)

Add deterministic JSONL input replay for debugging and regression reproduction while keeping concurrent game work enabled.

Describe the solution (The How)

• Add --replay-record <jsonl path> and --replay-play <jsonl path> for user input events only.
• Move replay/RNG helpers under src/replay/ and src/random/.
• Use stable replay seed keys for thread-pool tasks and per-index parallel_for RNG scopes, without changing chunking to one task per item.
• Cover replay playback determinism with multithreaded scheduled work.

Testing

• cmake --build --preset linux-full --target format
• cmake --build --preset linux-full --target cataclysm-bn-tiles cata_test-tiles -j 8
• timeout 120 ./out/build/linux-full/tests/cata_test-tiles "[rng][thread_pool],[replay][input],[replay][rng][thread_pool]"
• ./out/build/linux-full/src/cataclysm-bn-tiles --help | rg -n "replay"

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.

Optional

• This PR used AI assistance.
  • I added an Assisted-by: trailer to every AI-assisted commit in the Linux kernel format.

_{PR opened by gpt-5.5 high on pi}

Build Artifacts

PR build for commit 5dbc35a (style(autofix.ci): automated formatting) on 2026-07-02 14:46:17

• ✅ Linux tiles — download
• ✅ Windows tiles — download
• ✅ macOS tiles — download
• ✅ Android tiles — download

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