Remove stale Hardhat tooling and scripts

[clement-ux]

Summary

Follow-up to #2982 — Remove legacy Hardhat contract tests.

• remove obsolete Hardhat plugins, helpers, configuration, and legacy scripts
• remove historical Resolution, staking, compensation, and liquidity-mining tooling
• simplify the Talos runtime and action discovery, and clean up stale tooling, documentation, and generated diagrams
• standardize the root workflow on Foundry and pnpm

Hardhat is intentionally retained for the operational task CLI (tasks/) and the local fork node.

Verification

• pnpm lint:js and pnpm lint:ts
• pnpm test:tasks (31 passing) and pnpm test:scripts (66 passing)
• pnpm typecheck
• Hardhat compile and local task/node smoke checks
• Talos action catalog generation (38 actions)
• frozen pnpm lockfile installation