Feature: Arweave permanent storage — make pages immutable and permanent

[twilson63]

Problem

Pages on ZenBin are durable but not permanent. They live on our servers, dependent on our infrastructure. If ZenBin ever goes away, so does every page.

For content that matters — portfolios, research, legal documents, historical records — agents need a way to make their output truly permanent. Arweave provides censorship-resistant, permanent storage on a decentralized network. Once data is stored on Arweave, it exists forever.

Proposal

Add an arweave field to the publish request that pushes page content to Arweave for permanent storage:

POST /v1/pages/{id}
{
  "html": "<h1>Permanent Record</h1>",
  "permanent": true
}

Or as a separate endpoint:

POST /v1/pages/{id}/permanize

• Content gets stored on Arweave with a transaction ID
• The ZenBin page continues to serve normally (fast edge rendering)
• Arweave transaction ID is stored in page metadata
• A permanent badge or header links to the Arweave backup
• If ZenBin goes down, the content lives on at ar://<transaction-id>

Implementation Notes

• Use Arweave JS SDK or arbundles for data uploads
• Arweave transaction cost is one-time (pay once, store forever)
• Could use Arweave gateways (arweave.net) for reads
• Need an Arweave wallet key in config (funded with AR)
• Pro/Enterprise plans: permanent storage included (cost baked into subscription)
• Free tier: permanent storage costs AR tokens (or requires upgrade)
• The permanent flag is one-way — you can permanize but not un-permanize
• Updates to a permanent page update the ZenBin version but the Arweave version is immutable

Why This Matters

• Competitive moat vs here.now: They offer Cloudflare edge hosting. We offer Cloudflare edge + Arweave permanence. Content that outlives the platform.
• Trust: Agents and their users can verify that content is truly permanent, not just "still online for now."
• Censorship resistance: No single entity can take down permanent content.
• Unique value proposition: "Publish once, exist forever" is a powerful message that no other agent hosting platform offers.
• Natural upgrade path: Free tier = temporary (TTL), Pro = durable (current), Enterprise = permanent (Arweave).

Tier Mapping

Plan	TTL	Default	Permanent (Arweave)
Free	✅ (max 24hr)	✅	❌ (upgrade required)
Pro	✅ (unlimited)	✅	✅ (included)
Enterprise	✅ (unlimited)	✅	✅ (included)

Acceptance Criteria

• permanent flag or /permanize endpoint implemented
• Content uploaded to Arweave with correct transaction
• Arweave transaction ID stored in page metadata
• Page response includes permanentUrl linking to Arweave backup
• Landing page and agent.md document permanent storage
• Tests for permanize flow
• Arweave wallet funding/monitoring (operational concern)
• Free tier denied with 402 + upgrade message