Taxation breakdown screen in economy explorer

Goal

Add a taxation breakdown screen to economy-explorer — the tax analogue of the existing economy dashboards: where tax revenue comes from and where it lands.

Suggested content

• Rates in effect: current balance-tax brackets and per-plugin source/income-tax rates (sourced live — pairs with PAR-80, which would publish config into the DB; until then, read from treasury-rest-api / config).
• Collected over time: tax revenue by period, split by type — balance tax, source/income tax, ChestShop sales tax (chestshop-sales-tax), and fines (government_fines) — from the ledger_* tables filtered on the relevant plugin_system/memo tags.
• Where it lands: which GOVERNMENT account(s) receive tax, and totals.

Notes for the implementer

• Enumerate the actual plugin_system/memo tags the tax paths use (balance-tax job, chestshop-sales-tax from the ChestShop TaxApi path, fines) and group on those — don't assume tag names.
• Follow the explorer's SSR + caching conventions (lib/sql/* DAL + the SWR cache from PAR-156) and the financial-privacy posture (aggregates public).

Depends/relates: PAR-80 (live rates in DB), PAR-145 (plugin_system attribution makes the grouping reliable).