Summary

• Expose the full range-filter surface on list_budget_accounts(). The REST endpoint at /api/budget/accounts/ has always supported __gte / __lte lookups on every numeric metric (the 26 fields in the backend's RANGE_NUMERIC_FIELDS); the SDK previously only forwarded identity / taxonomy filters, so callers were forced to discover accounts by exact symbol lookup.
• Adds 78 explicit named kwargs (26 range fields × {exact, _gte, _lte}). Each maps to the API's field__gte / field__lte form. Per the SDK's filter-surface non-negotiable in CLAUDE.md, every new filter is an explicit typed parameter — no **kwargs passthrough. Mapping body is table-driven so the method body doesn't balloon with if val is not None blocks.
• Why now: the upcoming makegov.com blog post on the budget endpoint's discovery story (PR makegov/makegov.com#29) wants to show this query:

  client.list_budget_accounts(
      fiscal_year=2024,
      contract_share_of_obligated_capped_gte=0.6,
      ba_growth_next_year_pct_gte=0.15,
      unobligated_balance_gte=200_000_000,
      ordering=\"-unobligated_balance\",
  )

  Before this PR, that wasn't expressible in the SDK at all.

Compatibility

• Pure addition. Existing call sites are unaffected. Minor bump → 1.2.0.

Test plan

• uv run ruff format + uv run ruff check tango/ tests/ clean
• uv run mypy tango/ — Success: no issues found in 17 source files
• uv run pytest tests/ -m \"not integration and not production\" — 302 passed
• New unit tests cover: range filters serialize to field__gte / field__lte; default call (no filters) sends only paging + shape
• Live API smoke test against tango.makegov.com returned the expected 8 FY2024 accounts for the discovery query and matched the response from a hand-built HTTP probe