Update nightwatch75/dns-switcher to 0.1.2 — fix #292 review notes (#319)

Addresses the three non-blocking notes from #292:

- README's plugin_api requirement was stale (22) vs the manifest's real
  minimum (17, the onExit lifecycle addition) — corrected, and pinned the
  noctalia version floor to beta.7 (the first tagged release plugin_api
  actually reaches 17 in).
- apply()'s privilege path ran the whole discovery+mutate script through
  `priv sh -c '...'`, which the documented sudoers rule (NOPASSWD:
  /usr/bin/nmcli) never covers — sudo -n always failed. Now the privilege
  prefix is applied to each of the two mutating nmcli calls individually,
  never to a wrapping shell.
- Regenerated thumbnail.webp.

Co-authored-by: nightwatch75 <nightwatch75@users.noreply.github.com>

dns-switcher/plugin.toml

@@ -6,7 +6,7 @@
 
 id = "nightwatch75/dns-switcher"
 name = "DNS Switcher"
-version = "0.1.1"
+version = "0.1.2"
 plugin_api = 17
 author = "nightwatch75"
 license = "MIT"