V3 QuickBooks Online capability pack for the SMB-finance wedge. Declares canonical accounting operations over QuickBooks invoices, bills, expenses (Purchase), customer payments, refunds, customers, vendors, and the chart of accounts (Account). Reads flow after connection grant; invoice/bill/expense/customer/vendor writes ask + diff; customer-payment, refund, and invoice-void are destructive/always-ask so money movement never rides a session grant. Mirrors the shipped Stripe billing-pack entity_platform pattern. The READ surface is LIVE-VERIFIED against the QuickBooks Online sandbox (2026-06-13): OAuth token exchange, the /query endpoint (base https://quickbooks.api.intuit.com, /v3/company/<realmId>/query?query=<SQL>&minorversion=75 -> QueryResponse.<Entity>[]), single read-by-id (/<entity>/<id> -> {<Entity>}), realmId-in-path + sandbox base, and every read field_path all confirmed against live sandbox data. WRITE ops (create/update/void/payment/refund) are authored to the same documented v3 shapes but were NOT exercised live (non-mutating verification only). This is the QuickBooks catalog + money-write surface ONLY — the two vendor-agnostic accounting workflows (overdue-invoice-chase, accounting-daily-back-office) ship in the vendor-neutral `acct` pack (install it alongside this one for the workflows); their canonical `core.acct.*` read op-steps resolve against THIS vendor's catalog at run (dispatch-time), projecting QuickBooks' raw records to the canonical accounting fields. Canonical accounting op-steps are read-only; money writes ride the gated ingredient binding. See docs/unified-pack-exploration/smb-finance-wedge.spec.md.