Make the validated IDD-push zero-copy path the default for a fresh install,
without penalising dev / non-pf-driver runs:
- The shipped default config now enables it. Both seed sites set
`PUNKTFUNK_VDISPLAY=pf` + `PUNKTFUNK_IDD_PUSH=1`: the hardcoded default the
service writes on `service install` (`ensure_default_host_env`) AND the
`host.env.example` template the installer bundles. A fresh install therefore
runs the validated path (the installer also bundles the pf-vdisplay driver);
it falls back to DDA if the driver can't attach.
- `idd_push` is now **value-aware** instead of a bare presence flag, so an
operator can turn it OFF with `PUNKTFUNK_IDD_PUSH=0` in host.env — a `var_os`
presence check read `=0` as "on". Unset still ⇒ off (the code default is
unchanged, so existing host.env files and dev/CI runs are unaffected; only the
shipped default config opts in).
Also scrubbed the stale "SudoVDA" wording in host.env.example. Linux cargo
clippy -p punktfunk-host -D warnings clean; the service.rs default string is
Windows-only (CI-gated).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
enricobuehler
0bf3984614