Read the Billing history aggregate: usage by day or month and one page of the wallet ledger

Returns one read-only page DTO. history is wallet spend per UTC period (granularity day with periods up to 90, default 30; or month with periods up to 24, default 12; end optionally names the last day YYYY-MM-DD or month YYYY-MM), per category (calls, sms, numbers, recordings, translations, other), in the wallet's currency as integer minor units, with every period present. Spend is money the ledger recorded as spent; top-ups, refunds and call holds/releases are not spend. ledger is one page of wallet entries, newest first by (created_at, id), filtered by type (all, topup, call, sms, number, recording, translation, refund, hold, other) and an inclusive UTC date range from/to (YYYY-MM-DD, default the history window); pass next_cursor back as cursor while has_more is true. matching_count counts the filtered entries up to export_row_cap, and matching_count_exceeds_export_cap says the CSV export would be refused. calls_split divides the range's call spend into phone_line_minor (the carrier component's share of each hosted AI call, rounded down, or the whole of a call billed without hosted AI components) and ai_agent_minor (the rest); the two always add up to calls_minor. Each entry's amount_minor is how the entry reads to a customer: the amount spent, negative, for a charge (which is taken from an earlier hold), otherwise the change to available funds (a hold negative, its release positive, a credit positive); so amounts across a call's hold, charge and release do not sum to the balance change. available_delta_minor sums to the change in available funds and spent_delta_minor to spend. Entries carry only customer-safe fields: Stripe references in short form, a call_id only for a call in the same workspace, and an sms_conversation_id for an SMS charge. The ledger lists the whole organization's wallet, every project's entries alike, whatever project_id is passed (a project_id must belong to the session's organization, else 404). Each entry's project_id is the project of its call or SMS conversation (null when it has neither, or the conversation belongs to no project). The dashboard Calls and SMS pages read only the session's project, so the workspace links an entry's call or conversation only when the entry's project_id is that project. Tenant-bound to the bearer session; no provider request and no write.