feat(inspector): capture pipeline — AWS SDK middleware + ring buffer

[JSisques]

Summary

• Adds RequestEntry type with service, operation, input, output, durationMs, status, error, attempts fields
• Implements a module-level ring buffer (lib/aws/inspector-buffer.ts, cap 200, FIFO) to store captured SDK calls
• Implements a payload truncation utility (lib/aws/inspector-truncate.ts) that handles strings >4KB, Uint8Array, stream duck-types, and nested objects
• Adds withInspectorMiddleware Smithy middleware at the deserialize step to capture timing and $metadata.attempts
• Wires the middleware into all 6 AWS client factories: DynamoDB, Lambda, SNS, SQS, CloudWatchLogs, S3

Notes

• Ring buffer is process-scoped (resets on server restart) — intentional for a local dev tool
• Error shape enriched to { name, message, code?, statusCode? } instead of plain string (design decision)
• Chained PR — PR2 (Server Action + Store + UI) targets this branch

Test plan

• pnpm test passes with 0 failures in PR1 files (71 tests)
• Middleware records success + error entries with correct fields
• Buffer FIFO eviction at 200 entries
• Truncation handles all edge cases (string, binary, stream)
• All 6 client factories have INSPECTOR middleware tag