Adds build support for 32-bit x86 (i386/i686) and ARMv6 (older Raspberry Pi models) architectures across all agents and install scripts.
Changes:
- Add linux-386 and linux-armv6 to build-release.sh builds array
- Update Dockerfile to build docker-agent, host-agent, and sensor-proxy for new architectures
- Update all install scripts to detect and handle i386/i686 and armv6l architectures
- Add architecture normalization in router download endpoints
- Update update manager architecture mapping
- Update validate-release.sh to expect 24 binaries (was 18)
This enables Pulse agents to run on older/legacy hardware including 32-bit x86 systems and Raspberry Pi Zero/Zero W devices.