Implement Arkiv Fee System (V1)

[arrivets]

Implements the Arkiv Fee Function defined in
https://github.com/Arkiv-Network/arkiv-architecture/blob/main/arkiv/tokenomics/arkiv-fee-spec.md

V1 scope

• Pure deterministic fee function:
  fee_GLM = f(op, op_args, fee_multiplier, usd_per_glm)
• Six ops: CREATE_ENTITY, DELETE_ENTITY, SET_ATTRIBUTE, REMOVE_ATTRIBUTE,
  EXTEND_LIFETIME, CHANGE_OWNER
• Storage-rent term (size × time) for ops that allocate or extend storage
• Two governance scalars (fee_multiplier, usd_per_glm) plus seven cost knobs,
  all on-chain in a governance contract; per-chain fee_multiplier_max
• Fee collection via the standard OP Stack sequencer revenue path (spec §7)
• Permissionless DELETE for expired entities + a V1 cleanup bot (spec §2)
• Lightweight fee-estimation RPC for UX and pre-submit predictability (spec §8)

Sub-issues

• Implement Governance SmartContract #86 — Governance contract: stores all nine knobs, governance-writable with
  per-update caps and timelocks; deployed as a predeploy from genesis
• Implement Fee Function in EntityRegistry Precompile #87 — Precompile fee function: evaluates the pure formula and charges the
  fee via the EVM gas path on every entity op
• Calibrate Gas Constants #89 — Calibrate cost constants: profile arkiv-entitydb for real per-op $
  cost; sets initial values seeded by Implement Governance SmartContract #86
• Permissionless DELETE on expiry #90 — Permissionless DELETE on expiry: widen the DELETE_ENTITY auth check
  so anyone can call it once expiresAt has passed
• Cleanup Bot #91 — Cleanup bot: Golem-operated service that scans expired entities and
  calls DELETE_ENTITY, paying the standard fee
• Implement arkiv_estimateFee RPC #92 — arkiv_estimateFee RPC: lightweight, namespace-gated fee preview that
  doesn't simulate the full tx; returns GLM + USD + cost breakdown + knobs
  snapshot

Sequencing

• Implement Governance SmartContract #86 and Calibrate Gas Constants #89 can run in parallel; Calibrate Gas Constants #89 is data-gathering on existing code and
  does not block Implement Governance SmartContract #86 (placeholders seed initially, real values land later)
• Implement Fee Function in EntityRegistry Precompile #87 depends on Implement Governance SmartContract #86's ABI
• Permissionless DELETE on expiry #90 is independent and can land first
• Cleanup Bot #91 depends on Permissionless DELETE on expiry #90 being live on-chain
• Implement arkiv_estimateFee RPC #92 depends on Implement Fee Function in EntityRegistry Precompile #87 (pure function) and Implement Governance SmartContract #86 (contract ABI)

Out of scope (deferred to V2 per spec §10)

• Read pricing
• Refunds on early DELETE or REMOVE_ATTRIBUTE
• Downstream fee-distribution mechanics (burn / lock / foundation allocation)
• SDK cost-preview surface (eth_estimateGas × eth_gasPrice remains available
  as the authoritative real-tx GLM cost; Implement arkiv_estimateFee RPC #92 covers the lightweight UX path)
• Per-attribute-type indexing cost differentiation (spec §10.3 — V1 stance is
  type-blind, revisit if calibration shows >30% under/over-charge per class)