Revert "feat: add X-KiloCode-MachineId header to API requests"

[chrarnoldus]

Reverts #331

[kiloconnect]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

This is a clean revert of PR #331 (feat: add X-KiloCode-MachineId header to API requests). The revert completely removes all traces of HEADER_MACHINEID / X_KILOCODE_MACHINEID from the gateway constants, headers, barrel exports, and LLM request headers. No dangling references remain in the codebase. The Identity.getMachineId() function still exists in kilo-telemetry for telemetry purposes, which is unrelated and unaffected.

Files Reviewed (4 files)

• packages/kilo-gateway/src/api/constants.ts - Removed HEADER_MACHINEID constant
• packages/kilo-gateway/src/headers.ts - Removed HEADER_MACHINEID import, X_KILOCODE_MACHINEID re-export, machineId option from buildKiloHeaders, and conditional header setting
• packages/kilo-gateway/src/index.ts - Removed HEADER_MACHINEID from barrel export
• packages/opencode/src/session/llm.ts - Removed HEADER_MACHINEID and Identity imports, machineId resolution, and machine ID header from requests