chore(store,topo): bound store to fixed-32

[lidatong]

Closes #8222

SUMMARY
              Total Tiles: 43
      Total Memory Locked: 512197939200 bytes (477 GiB + 22 MiB + 20 KiB)
  Required Gigantic Pages: 476
      Required Huge Pages: 523
    Required Normal Pages: 921
  Required Gigantic Pages (NUMA node 0): 476
      Required Huge Pages (NUMA node 0): 523

[github-actions]

Performance Measurements ⏳

Suite	Baseline	New	Change
backtest mainnet-368528500-perf per slot	0.061347 s	0.061206 s	-0.230% ✅
backtest mainnet-368528500-perf snapshot load	3.241 s	2.493 s	-23.079% ✅
backtest mainnet-368528500-perf total elapsed	61.347182 s	61.206398 s	-0.229% ✅
firedancer mem usage with mainnet.toml	966.37 GiB	1196.37 GiB	23.800% ⚠️

[Copilot]

Pull request overview

This PR reduces memory usage by bounding the store to fixed-32 shreds per FEC set, enabling an increase in max_live_slots from 512 to 4096 (addressing issue #8222) while keeping total locked memory within the 512 GiB limit of target hardware.

Changes:

• FD_STORE_DATA_MAX reduced from 63985 to 31840 bytes, reflecting fixed-32 FEC set sizes (32 shreds × 995 bytes payload = 31840, matching FD_SHREDDER_NORMAL_FEC_SET_PAYLOAD_SZ)
• Store fec_max sizing formula in topology.c replaced from a temporary hardcoded * 1024UL hack with the semantically correct * FD_SHRED_BLK_MAX / FD_FEC_SHRED_CNT
• max_live_slots default increased from 512 to 4096

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/disco/store/fd_store.h	Reduces FD_STORE_DATA_MAX from 63985 to 31840 to reflect fixed-32 FEC set constraint
src/app/firedancer/topology.c	Replaces temporary * 1024UL hack with correct * FD_SHRED_BLK_MAX / FD_FEC_SHRED_CNT formula
src/app/firedancer/config/default.toml	Increases max_live_slots from 512 to 4096

[Copilot]

The comment block above FD_STORE_DATA_MAX still describes the old computation ("67 shreds per FEC set * 955 payloads per shred = 63985 bytes max"), which no longer matches the new value of 31840. The comment should be updated to reflect the fixed-32 basis: 32 shreds per FEC set × 995 bytes payload per shred = 31840 bytes max (matching FD_SHREDDER_NORMAL_FEC_SET_PAYLOAD_SZ in fd_shredder.h).

[github-actions]

Performance Measurements ⏳

Suite	Baseline	New	Change
backtest mainnet-368528500-perf per slot	0.061192 s	0.061107 s	-0.139% ✅
backtest mainnet-368528500-perf snapshot load	3.288 s	2.479 s	-24.605% ✅
backtest mainnet-368528500-perf total elapsed	61.191652 s	61.106743 s	-0.139% ✅
firedancer mem usage with mainnet.toml	966.37 GiB	1196.37 GiB	23.800% ⚠️

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

[github-actions]

Performance Measurements ⏳

Suite	Baseline	New	Change
backtest mainnet-368528500-perf per slot	0.075007 s	0.075244 s	0.316% ✅
backtest mainnet-368528500-perf snapshot load	4.198 s	3.191 s	-23.988% ✅
backtest mainnet-368528500-perf total elapsed	75.006532 s	75.244321 s	0.317% ✅
firedancer mem usage with mainnet.toml	964.37 GiB	1179.37 GiB	22.294% ⚠️