Migrate iDX6011 Pro support to upstream v0.4-beta

[0x556c79]

Summary

• migrate the idx6011 profile from the temporary third-party fork to official upstream v0.4-beta, pinned to c830a2293cf5c67c58e5a98ca339b089b2b13fc3
• select the beta automatically only for exact DMI product iDX6011 Pro; preserve stable master behavior for every other automatic selection
• use the tagged gh-actions/build-scripts/truenas/build/tags/v0.4-beta artifacts and require an exact TrueNAS version
• validate downloads before atomic cache replacement and record tag, commit, and artifact path in source markers
• defer beta loading to the upstream probe with its SMBus/network/disk parameters
• update the dual-network monitor for netdev/netdev2, preserving deterministic NIC ordering and the exact legacy override migration
• refresh README, changelog, and agent architecture guidance

Why

Upstream now carries iDX6011 Pro support, so the installer no longer needs to use the third-party implementation as its active source. Upstream PR #104 was not tested on iDX6011 Pro hardware and differs from the working fork's initialization sequence, so this migration remains hardware-gated.

Safety and impact

• Do not merge until real iDX6011 Pro hardware acceptance passes.
• The fallback build workflow, build-scripts/truenas/, and remote idx6011-kmods branch remain untouched for rollback.
• Stable DX/DXP selection and loading behavior remains on upstream master.
• iDX6011 and iDX6012 remain explicit manual beta overrides.
• A beta probe failure stops installation before disk/network monitors start.
• Rollback uses the installer at pre-migration commit b3ce00f.

Validation completed

• git diff --check
• bash -n install_ugreen_leds_controller.sh
• shellcheck install_ugreen_leds_controller.sh
• help output
• stable and beta profile-selection contracts
• exact beta URL resolution and missing-artifact failure behavior
• third-party marker migration followed by tagged-cache reuse
• generated beta and stable probe scripts pass bash -n
• generated multi-network monitor passes ShellCheck
• official 25.10.5 artifact resolves and reports:
  • vermagic 6.12.95-production+truenas
  • write_protocol
  • num_netdev_leds
  • num_disk_leds

Hardware acceptance still required

• explicit --controller-source idx6011 preflight and install
• loaded parameters are smbus-block, 2, and 6
• LEDs are power, netdev, netdev2, and disk1-disk6
• rolling boot animation stops
• both LAN LEDs show independent activity
• all six disk LEDs work without disk7/disk8 errors
• probe, disk, and network services remain healthy without I2C/status errors
• auto selects the same beta profile and reuses the cache
• reboot reuses the tagged module with the same parameters
• after acceptance, remove the temporary fallback workflow/build tree before merge

Refs #23