Add finalized pricing table to docs.filecoin.cloud

## Goal

Publish the finalized list-price table on docs.filecoin.cloud (\`sites/docs/\`) so customers and SP partners have a single canonical reference instead of digging through Linear, sheets, and PRs.

## Source material

- **Pricing Model Framing - UX vs SP Costs** (Tim's framing doc): https://docs.google.com/document/d/1wLIONYjT15rSPMmphpNR1GmebtKhEwpMaAYpjo0HtV8/edit
- [Pricing Proposal sheet](https://docs.google.com/spreadsheets/d/17tnkZgdPYB4D0YurbcmFBeUsCnHyWbvanWQmjH4lBL0/edit) — \"Proposal\" tab, column F (\`PRICE LISTED\`)
- [filecoin-services#468](https://github.com/FilOzone/filecoin-services/issues/468) — rationale doc (the why behind each fee)

## Scope

- Add a Pricing page (or section) to \`sites/docs/\` with the finalized list-price table:
- Sybil / Network Congestion Fee
- Data Set Creation (SP gas-cover)
- Recurring per-data-set proving floor
- Stored Data (per-copy + default replication)
- Per Add Piece (operation, batch limit)
- Per Piece / Batch Delete
- Data Set Deletion
- Terminate Service
- Egress / Bandwidth
- Repair Costs (no separate line — backstop note)
- Link to the rationale doc in [filecoin-services#468](https://github.com/FilOzone/filecoin-services/issues/468) for the \"why\"
- Mirror the structure of the framing doc (UX vs SP costs split) so customers see what they pay vs what SPs absorb

## Dependency

**Blocked by [filecoin-services#470](https://github.com/FilOzone/filecoin-services/issues/470)** — Verify premium gas costs and update final pricing. Numbers cannot be published until premium-inclusive list prices are confirmed by Luca; otherwise the published table will need to change shortly after launch.

## Out of scope

- Rationale / decision history (lives in [#468](https://github.com/FilOzone/filecoin-services/issues/468), not on the public docs site)
- IPFS pricing (deferred to on-ramps)
- Volume tiers for egress (post-GA)