Categorises the terminal error of a failed interception and persists it
on the interception record, then surfaces it on the AI Gateway API.
- Categorise into an enum (`bad_request`, `unauthorized`,
`rate_limited`, `overloaded`, `server_error`, `unknown`), unwrapping
the ResponseError envelope, the upstream Anthropic/OpenAI SDK errors,
and key-pool exhaustion so blocking and streaming paths agree.
- Thread the type and raw message through the recorder dRPC into the
`aibridge_interceptions` row (optional proto fields; NULL on success).
- Expose the error on the AI Gateway thread API from the root
interception.
*This PR was produced by opencode (agent) using the `anthropic/claude-opus-4-8` model, under human direction and review.*
Danny Kopping
ef0b5585d5