Add player replay prototype harness

[Dryxio]

What changed

Adds a client-side replay prototype under test-resources/replay-prototype to validate the replay concept before moving capture/playback into native C++.

The harness:

• records the local on-foot player into a 60-second rolling in-memory buffer
• samples at roughly 60 Hz using timestamps rather than frame numbers
• captures transform, velocity, camera, aim endpoint, weapon state and key control states
• spawns a semi-transparent local ghost ped for playback
• replays ped control states and aim target
• applies 500 ms transform keyframes with soft drift correction and hard resync thresholds
• supports play, pause, resume and seek
• displays sample count, buffered duration and correction/resync metrics

Test commands

/replayrec
/replaystop
/replayplay [startSeconds]
/replaypause
/replayresume
/replayseek <seconds>
/replaydebug
/replayclear

Scope

This is deliberately the first working validation harness: on-foot/local-player only, no vehicles, persistence, network upload, surrounding entity capture or anti-cheat scoring yet. If control-driven playback proves stable across FPS changes, the recorder/ring buffer can move into the native client layer while keeping a small Lua-facing control API.

Validation

Reviewed the branch diff against master and kept the change isolated to a new test resource. GitHub Actions/build results are intentionally not awaited for this prototype.