Capstone: ship Smart Ledger
Assemble the product
This capstone starts empty—there is no fake ledger. A real user adds their own transactions. The app validates and normalizes input, stores amounts as agorot, persists locally, derives KPIs, filters rows, deletes entries, and exports a JSON backup.
The export is a real artifact. The storage is real browser storage. The only limitation is deliberate: this learning project never connects to a bank and never asks for banking credentials.
操作说明
Implement loadTransactions and saveTransactions using localStorage and JSON.
提示： Restore [] on parse failure; stringify transactions on every mutation.
这段代码写在哪里？
// Assemble: load/save, validation, add/delete, derived KPIs, filter, and JSON export.写在第 5 行——在那条注释下方，接在你已经写好的代码后面。
Validate and normalize input in createTransaction.
Render KPIs and filtered rows from the transactions array.
Implement add and delete flows, saving after each mutation.
Export a real JSON backup with Blob and URL.createObjectURL.
你的代码
描述你想为这一步构建的内容，我来编写代码——然后点击「应用」把它放进你的编辑器。 本步骤：Implement loadTransactions and saveTransactions using localStorage and JSON.