Document Eden v0.4.0

[nuke-web3]

Introduces a page on "why eden" that covers novel things ev-reth give over a generic EVM clone, specifically focused on the 0x76 tx type.

Resolves https://linear.app/celestia/issue/DEVX-24/document-eden-v040-app-based-gas-sponsorship-batch-tx-move-away-from

[jcstein]

Heads-up: #152 (bun standardization) just merged to main, so this branch needs a rebase — and the lockfiles need cleanup along the way. This PR currently touches bun.lock, bun.lockb, and yarn.lock; after rebasing, main should win on all three:

• delete bun.lockb — it was generated by bun 1.1.x; the repo standardized on the text-based bun.lock (bun >= 1.2, see README). Committing both formats risks them silently drifting apart.
• don't resurrect yarn.lock — it was removed in chore: standardize on bun for dev and CI #152.
• take main's bun.lock — it was regenerated from scratch there (the yarn-migrated one didn't link bins). If this PR adds/changes deps, re-run bun install after the rebase with bun >= 1.2 (bun upgrade if needed) so the lockfile updates cleanly on top.

The bun >= 1.2 bit also explains the slow first install you hit on the other branch — 1.1.29 can't read bun.lock, so it did a full unpinned resolve.

[jcstein]

Reviewed the new /why-eden page and homepage changes. Good, well-scoped docs PR — I verified the 0x76 material against the ev-reth README and the core claims (batch atomicity, dual-signature scheme, refunds routing to sponsor) are accurate, and both external links resolve.

Two things I'd want resolved before merge (inline comments have details):

1. The "No mempool, no MEV" framing overstates — ev-reth's own README documents a txpool, and "execute in the order submitted" rests on trusting the sequencer's discretion rather than a protocol guarantee.
2. 128 KB contract limit needs confirmation — in ev-reth it's an opt-in chainspec setting (contractSizeLimit, with EIP-170 applying before the activation height), not a default. Worth confirming Eden mainnet's chainspec actually sets it before we promise it to developers.

The rest is polish — heading hierarchy, a few wording nits, and finishing the "Celestia Eden" → "Eden" rename on the homepage. The WIP callout gives some cover, but #1 and #2 are developer-facing promises people will design around.

[gbarros]

I didn't dive too much in the details (as in if a specific information is correct); but I read through it and it is looking good!
it's very clear and easy to grasp.

[jcstein]

LGTM!