v1.14.0 — Immutable selected-run usage and cost

CI runs now retain selected-model estimates from the exact executed revision and a dated, immutable rate snapshot. The new owner-scoped /projects/{id}/usage/v1 read separates complete estimates, partial known charges, unavailable coverage and legacy stored amounts; project edits and feedback never reprice historical runs. Native accounting preserves cache/reasoning semantics and effective returned model/tier, while normalized OpenCode usage remains explicitly incomplete.

Adds migration a0b1c2d3e4f5 with append-only rates and protected run attribution. No prices or runtime activation are seeded. Native agents emit optional model/tier fields only when configurations advertise B15 support, preserving older payloads. Existing costs and savings endpoints remain compatible. Actual migration, rates and deployment require separate operational approval.

Validation: full fake PostgreSQL 16 suite 1,198 passed / 40 opt-in skipped; after final telemetry/attribution refinements, all agent tests and affected billing/API/migration suites 514 passed / 29 opt-in skipped. Wheel build and diff checks pass. Existing Starlette deprecation warning remains. No paid/live model calls.

Releases: backend 1.13.0 -> 1.14.0 MINOR for additive owner usage API and immutable billing functionality. Agents 1.7.0 -> 1.8.0 MINOR (both shared-sequence images) for compatible negotiated response telemetry; request profiles, limits and gate behavior are unchanged. Fresh tags, Releases and GHCR versions checked. Publication is separate from deployment.

Publication verified September 24, 2026: successful release workflow; empty-config anonymous GHCR pulls and matching OCI version/revision labels.

• ghcr.io/steve-droid/driftplain-backend@sha256:8098e3ee1bde4f4f8313e743c05a1bbde02a0020f169c5fddb7dcd66948f862b
• ghcr.io/steve-droid/driftplain-agent@sha256:dc9d85cdc7ee7a7fe551e4714e1d62c9e75b1ab508e801a75a216820cc26c06c
• ghcr.io/steve-droid/driftplain-agent-security@sha256:95033f3166f688a9fad51dca6932b6f6dc6fa58136a5e9e862f374ac8700c53d

Review-agent first push hit GHCR unknown blob; the tag was confirmed absent and only the failed matrix job was rerun successfully. Existing artifacts were not overwritten.