[chandarith-chea]

Problem

docker version couldn't tell engine builds apart. /version returned GitCommit "preview", no build time, and only a dockivad component, so the CLI's Engine section showed blank Go version, commit and build date:

 Engine:
  Version:          0.18.0
  API version:      1.45 (minimum version 1.24)
  Go version:
  Git commit:
  Built:

Fix

go build already records the commit in the binary (vcs.revision, vcs.time, vcs.modified); the shipped v0.6.9 dockivad carries af13b2b. dockivad/api.go now reads it with debug.ReadBuildInfo:

• GitCommit: the first 12 characters of the commit, with -dirty for uncommitted changes. A build outside a git checkout reports unknown.
• BuildTime: the commit's time, so a rebuild of the same commit reports the same value.
• An Engine component with those details, as dockerd returns. dockivad stays the first component, because verify_dockivad.py checks Components[0].

No build script change. Version stays 0.18.0 and the API version stays 1.45.

Tested

• go test -race ./... in dockivad: ok. TestAPIContractAndRejectedOptions now checks the commit and both components.
• A bundle built from this branch with bundle_dockiva_engine.py: verify_dockivad.py --new-home 31/31.
• docker version against that bundle's engine:

 Engine:
  Version:          0.18.0
  API version:      1.45 (minimum version 1.24)
  Go version:       go1.27.2
  Git commit:       731ce0056d4f
  Built:            Sat Nov 14 02:55:50 2026
  OS/Arch:          linux/arm64
  Experimental:     true