This is the standalone V5 mod-facing backend. Never copy V4 handlers, migrations, bindings, object layouts, or wire behavior unless a V5 design document explicitly requires it. src/env.ts is the only place to declare Worker bindings, vars, and secrets.
A Bundle is the smallest upload, R2 storage, and delivery unit: exactly one Run and zero or one Screenshot. The Bundle prefix is 16 bytes — ASCII BPPBNDL5, a u32 big-endian version, and a u32 big-endian manifest length. A Bundle carries at most 30 Battle projections (MAX_BATTLES_PER_BUNDLE), and duplicate battle_id values inside one Bundle are invalid.
Bundle upload is intentionally unauthenticated: uploader_account_id and bundle_uploaders are caller assertions, never authentication or authorization facts. bundle_uploaders starts empty, records only successful V5 Bundle uploaders, and is updated as the final Bundle commit statement with ON CONFLICT DO NOTHING. Ghost projection accepts only a self opponent or an opponent already present in bundle_uploaders; filtered history is never backfilled. A repeated (uploader_account_id, battle_id) across Bundles is anomalous: preserve the first projection and record a metric, and never merge fields across Bundles.
The Worker never exposes a Bundle download proxy and never decompresses the Run payload during ingest. Protected routes authenticate before parsing or querying, and GET /ghost-battles calls its rate-limit binding before business query parsing or D1 access. R2 object retention is an externally provisioned 8-day lifecycle rule, and every issued presigned URL is a seven-day S3 GetObject capability.
All public HTTP paths are listed in docs/api-reference.md; adding a route requires updating the route table, contract tests, and the API reference together. Tests exercise public module interfaces — storage adapter tests may inspect schema and query plans only when the migration or SQL statement is the interface under test.
Use a clear, correctly capitalized, imperative PR title with no conventional-commit prefix and no trailing punctuation. End the body with Release Notes: and one Added/Fixed/Improved bullet, or N/A for backend-internal work.