## Summary
Add circuit breaker support for AI Bridge to protect against cascading
failures from upstream AI provider rate limits (HTTP 429, 503, and
Anthropic's 529 overloaded responses).
## Changes
- Add 5 new CLI options for circuit breaker configuration:
- `--aibridge-circuit-breaker-enabled` (default: false)
- `--aibridge-circuit-breaker-failure-threshold` (default: 5)
- `--aibridge-circuit-breaker-interval` (default: 10s)
- `--aibridge-circuit-breaker-timeout` (default: 30s)
- `--aibridge-circuit-breaker-max-requests` (default: 3)
- Update aibridge dependency to include circuit breaker support
- Add tests for pool creation with circuit breaker providers
## Notes
- Circuit breaker is **disabled by default** for backward compatibility
- When enabled, applies to both OpenAI and Anthropic providers
- Uses sony/gobreaker internally via the aibridge library
## Testing
```
make test RUN=TestPoolWithCircuitBreakerProviders
```
Fixes all our Go file imports to match the preferred spec that we've _mostly_ been using. For example:
```
import (
"context"
"time"
"github.com/prometheus/client_golang/prometheus"
"golang.org/x/xerrors"
"gopkg.in/natefinch/lumberjack.v2"
"cdr.dev/slog/v3"
"github.com/coder/coder/v2/codersdk/agentsdk"
"github.com/coder/serpent"
)
```
3 groups: standard library, 3rd partly libs, Coder libs.
This PR makes the change across the codebase. The PR in the stack above modifies our formatting to maintain this state of affairs, and is a separate PR so it's possible to review that one in detail.
Susana Ferreira