Filecoin Beam ("withCdn") support

[SgtPooki]

Purpose

This issue is a placeholder for tracking the work and notes about adding Filecoin Beam / withCDN support.

This issue is intended to cover all filecoin-pin areas including:

• CLI command arguments
• CLI status ouptut denoting whether a pieceCid has Filecoin Beam support
• CLI output providing download links using Filecoin Beam CDN
• Changes to pricing

Notes on pricing

Problem

The current payment system only considers storageInfo.pricing.noCDN.perTiBPerEpoch pricing, but CDN storage has different costs. However, @jennijuju has recently indicated this should NOT be implemented now because Filcdn is changing their billing model from fixed fees to egress-based fees.

Current State

The codebase hardcodes noCDN pricing in multiple payment calculation functions.

Where Changes Would Be Needed

• src/synapse/payments.ts
• src/payments/status.ts
• src/payments/interactive.ts
• src/payments/setup.ts
• src/payments/auto.ts

[BigLep]

I expanded the scope of this issue and its issue description to be about generally adding Filecoin Beam support to filecoin-pin.

[BigLep]

Relevant internal slack threads about timing of this functionality (it won't be present for 10/15):

• https://filecoinproject.slack.com/archives/C095WFA0QK1/p1759497061085179
• https://filecoinproject.slack.com/archives/C095WFA0QK1/p1759826627852839

[bajtos]

Here is the FilBeam roadmap issue tracking our side of this feature: filbeam/roadmap#85