[WIP] Gloas Mainnet Checklist

## Must

### Fork transition
#### Untracked
- [ ] Diagnose missed block 0 at fork https://discord.com/channels/593655374469660673/1372263082415493200/1527622997836566538
- [ ] Extract `eeb1c13`/`a8c50ce` from devnet 7 branch to their own PR

### Sync
#### Issues
- [ ] #9660
- [ ] #9224
- [ ] #9060
#### PRs
- [ ] #9661

### Mainnet scale
#### PRs
- [ ] #9350
#### Untracked
- [ ] EIP-7688 perf optimization round (ACD pre-testnet gate; land the ~20% POC optimizations)

### Fork choice
#### Issues
- [ ] #7637 for gloas / #9295 (compliance tests)
#### PRs
- [x] #9654
- [ ] #9233
- [ ] #9670

### Non-finality
#### Untracked
- [ ] Bounded checkpoint-state retention / no OOM under non-finality (#9489/#9490 closed unmerged, re-open direction); bound SeenPayloadEnvelopeInput (#9073)

### Builder
#### Issues
- [ ] #9296
#### PRs
- [x] #9595
- [ ] #9594
#### Untracked
- [ ] Remote-vs-local bid comparison + fallback + builder boost factor (blocked on beacon-APIs #625 / keymanager-APIs #87 / builder-specs merging)

## Should

#### Issues
- [ ] #5671 (envelope archive never pruned — simple prune first, dedup later)
- [ ] #9691
#### PRs
- [x] #9486
- [x] #9625
#### Untracked
- [ ] Gossip REJECT validation gaps: executionPayloadEnvelope.ts:78, payloadAttestationMessage.ts:85, block.ts:167
- [ ] Pre-publish envelope validation (miss slot instead of publishing network-rejected envelope)
- [ ] PTC epoch-436 residuals: fork-choice.ts:1630 UNKNOWN_PAYLOAD_STATUS review, BAL re-serialization check

## Post-mainnet

#### Issues
- [ ] #9690 (FCR rework) / #9648 (light client)
- [ ] #6602 / #9298 (builder economics)
- [ ] #9596 / #8028 / #9677 (rewards optimization)
- [ ] #9013 / #9014 / #9341 / #9395 (perf, unless devnets prove painful)
- [ ] #9441 / #9201 / #9558 / #9626 (post-activation cleanup)
- [ ] #9956 (blob deprecation)
#### PRs
- [x] #9681
- [ ] #9687
#### Untracked
- [ ] Block production refactor (separate gloas path), cache-sizing/timing TODOs, validator-monitor envelopes, RLP residue, networking spec-runner investigation, post-gloas merkleProof cases