Fix/stripe invoice webhooks

[sinatayebati]

Description

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Related Issues

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• Closes #

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Refactoring (no functional changes)
• Documentation update
• CI / infrastructure change

Contributor Checklist

• I have read the Contributing Guidelines
• make lint passes with no errors
• make test-unit passes
• I have added or updated tests that cover my changes
• I have updated documentation where necessary
• My commits follow the project's commit message conventions

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Note

High Risk
Changes core Stripe overage charging, invoice webhook ordering, and period closure—errors could double-charge, miss revenue, or close the wrong billing period.

Overview
Introduces durable billing reports so usage overages are reserved in Postgres (billing_reports) with frozen Stripe payloads, then delivered asynchronously with retries—replacing the previous pattern of creating InvoiceItems inline and advancing watermarks immediately.

Stripe renewal flow is tightened: overages target the invoice’s ending period (from period_start/period_end), draft invoices get last-chance capture, finalized invoices roll charges to carryover, and invoice.paid stages closure markers without rebilling the wrong month. Subscription period advances are forward-only so delayed webhooks cannot rewind billing. A Celery dispatcher recovers pending reports and checks recently closed periods for late Redis counters.

Also bumps release to v0.7.0, default judge model to vertex_ai/gemini-3.5-flash-lite, upgrades LiteLLM, expands judge picker models, and makes batch/single eval run names optional in the dashboard (field moved below Model).

Deploy: run migration fd38fefe55a8 before rollout; avoid running legacy and new overage reporters in parallel.

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