deploy.sh no longer starts units a live session already runs

`sync` on a box with a live session on it was unsafe in two independent ways, found by
preflighting the run rather than performing it. Refs #44.

**`enable --now` would have armed a screen lock mid-session.** The unit loop started every
`systemd-user/` unit whose `ExecStart` resolves. `swayidle-lock.service` on blankpad is
`enabled`/`inactive` — nothing started it, no swayidle process exists, `autostart.kdl` does
not launch one — so one `deploy.sh` would have begun blanking and locking the monitors while
the operator was mid-sentence. `live-sync.service` is `linked`, driven by its timer, and
`--now` forces a heartbeat commit at an arbitrary moment. A unit is now started only when
systemd reports it as nothing-yet (`""`/`disabled`), which is precisely a fresh box; anything
already installed is merely `enable`d. The state has to come from the **printed state**:
`is-enabled` exits 1 for `linked` exactly as for `disabled`, so exit status cannot
distinguish "installed, timer-driven" from "never installed" — the first version of this fix
got that wrong and the test caught it.

**`--check` output was being read as more than it can mean.** It prints `RELINK` for every
path the `zz` tier carries, even when the live link already points at the override
(`rules.kdl`, `keybinds.kdl`, `misc.kdl`, `autostart.kdl`, `.zshrc` all did on blankpad),
because the walk visits the base package first and reports the intermediate owner change.
The sentence committed in #43 — RELINK noise is "the sound of a stale override waiting" — is
too strong and is corrected: the line proves a pending change only when `readlink` shows the
live target is not already the `zz-$HOST` file, and `actions=0` is the honest summary. The
stale-override hazard #43 removed was and is real; the signal for it is the target, not the line.

**The dconf dump carried six of its 24 keys from another box**, none of them preferences:
a Firefox file-chooser `last-folder-path` of `/home/dank/Downloads`, a nautilus
`window-state` section, and `picture-uri`/`picture-uri-dark` pointing at
`file:///home/dank/.config/background`. The last five showed no conflict because blankpad's
live tree *already* held those `/home/dank` values — an earlier deploy wrote them here — and
a foreign value that agrees with live is invisible to any diff while still being wrong. They
are dropped; `picture-options='zoom'` stays, because it is a preference. The live wallpaper
URIs are cleared on the box as part of landing this (niri draws the wallpaper, noctalia owns
it, nothing reads a dead path).

`tests/deploy.bats` grows by four, over a stub `systemctl` — the real one on this box is
exactly what must not be invoked from a test. Red before: an already-`enabled` unit and a
`linked` unit both get `--now`. Green after, including the two directions that keep the
change honest: a `disabled` unit is still `enable --now`'d so a fresh box comes up, and a
unit whose `ExecStart` is absent here is never touched at all.

Verification: `bats tests/` 70/70, `kb-lint.sh omp-docs` 0, `kb-coverage.py` 0. The dump now
reconciles against live state with **0 conflicts and no `/home/` values in 18 keys**, proven
by key-by-key comparison rather than `diff` — `dconf load` writes only the keys present, so a
diff overstates the damage one way and hides it the other.

omp-docs/inventory/home-config-census.md

@@ -135,7 +135,7 @@ configs).
 | Reason | Contents |
 |---|---|
 | **Generated palette expansion** | Every `themes/noctalia*`, `*/noctalia.*`, `*/colors/noctalia*` / `Noctalia*` (24 files outside app-profile dirs). Machine-written by matugen/noctalia, not hand-authored: the `stat -c '%y %n'` cluster `2026-10-14 19:05:40.330…40.813 -0700` writes 24 files in one second (`alacritty/themes/noctalia.toml` at `.330212397`, `btop/themes/noctalia.theme` at `.334212456`, `tmux/themes/noctalia.conf` at `.813219586`, …); later re-runs re-stamp singles — `bat/themes/noctalia.tmTheme` `2026-10-18 17:11:22`, `niri/noctalia.kdl` `2026-10-18 17:36:27`, `mango/noctalia.conf` `2026-10-17 18:23:37`. A same-second mass-write is generation, never an edit. |
-| **App state / profiles** | `mozilla` (5471), `unity3d` RimWorld state (235), `nirimod` (116), `obsidian` (99), `FreeTube` (56), `google-chrome-for-testing` (5); plus per-program state inside tracked dirs: `dconf/user`, `fish/fish_variables`, `micro/syntax/*`+`micro/buffers/history`, `gtk-4.0/servers`, `cachyos/cachyos-hello.log`. |
+| **App state / profiles** | `mozilla` (5471), `unity3d` RimWorld state (235), `nirimod` (116), `obsidian` (99), `FreeTube` (56), `google-chrome-for-testing` (5); plus per-program state inside tracked dirs: `dconf/user`, `fish/fish_variables`, `micro/syntax/*`+`micro/buffers/history`, `gtk-4.0/servers`, `cachyos/cachyos-hello.log`. State hides inside a tracked file too: `dconf/dump.txt` carried `last-folder-path`, a nautilus `window-state` section and `picture-uri`/`picture-uri-dark` — all `/home/dank` values, and the wallpaper URIs were live on blankpad, i.e. already deployed here — dropped by #44, see [tools/dotfiles-deploy](/tools/dotfiles-deploy.md). |
 | **Skills-CLI installs** | `crush` (37), `devin` (37), `goose` (37), `kimchi/harness` (37) skill trees — provisioned by the skills CLI, owned by the store, not this repo. See [skills/store-wiring](/skills/store-wiring.md). |
 | **Secret tier** | `~/.config/secrets/` (`gitea`, `hf_token`, `hf_token_write`, `kagi_api_key` — names only), top-level `frank-job-hunt.env`, `containers/systemd/postgres.env`. Never tracked, values never printed. |
 | **Trash committed inside the tree** | `dotfiles/niri/.config/niri/cfg/.AGENTTRASH/display.kdl.superseded` — a retired output config committed 2026-10-09, five days before `.gitignore:54` gained `.AGENTTRASH/` (2026-10-14). Tracked-then-ignored: an ignore rule never reaches an already-tracked path, so the only repair is `git rm --cached`, done by #41. The rule does match at depth — `git check-ignore --no-index -v dotfiles/niri/.config/niri/cfg/.AGENTTRASH/x` resolves to `.gitignore:54` — so a fresh in-tree trash dir is ignored from birth and this does not recur on its own. |