feat(gateway)!: unify inclusive token accounting and explicit caps

[drewstone]

Input and output usage now represent inclusive provider totals, so reasoning and tool details are not charged twice.
The gateway omits separate detail caps unless the host explicitly supplies them; explicit caps, including zero, still require measured usage and enforcement.
New quotes use inclusive totals and the provider-cost ceiling.

Historical payment outbox and A2A finalization records retain their original additive accounting and settlement amounts.
New records persist an inclusive accounting basis.
Incomplete historical receipts fail rather than substituting zero for missing details.
The README documents the 0.11.0 adapter migration and historical-record constraints.

Validation: 488 tests pass under Node 24.18.0 and 22.22.2; typecheck and build pass.
Real payment/recovery fixtures cover inclusive settlement, explicit caps, omitted details, acknowledgement loss, repeated recovery, and incomplete historical receipts.
Three deliberate mutations fail: invented detail caps, reinterpretation of historical accounting, and double billing of detail counts.

[tangletools]

Reviewed the changed dispatch, settlement, reservation, and recovery paths at e6a98ac. Inclusive input/output totals own new charges; explicit detail caps remain enforced. Historical additive records retain their original arithmetic, and incomplete historical receipts now fail closed in both payment recovery and A2A finalization. Reviewed the 16-versus-22-unit settlement and acknowledgement-loss regressions, plus the historical missing-detail correction. Reported validation: 488 tests, typecheck/build, and both configured CI runtime lanes pass. Live payment failure receipt propagation remains a separate tracked follow-up; this change does not claim that proof.