Add nightwatch75/dns-switcher 0.1.1 (#292)

Switch the system DNS between popular providers, custom servers, or the ISP
default, from a panel on the bar — no reconnect, no captive-portal re-run.
Detection reads the active connection's own ipv4.dns/ipv4.ignore-auto-dns
instead of guessing, so a manually configured resolver (LAN ones included)
shows as its provider and DHCP-assigned DNS shows as Default (ISP). A
singleton service entry owns detection/apply so multiple bars share one
engine.

Every bar gesture (left/right/scroll) is a manifest [widget.actions] default,
resolved through noctalia's own IPC registry, so any of them can be remapped
from the bar's own gesture settings without touching the plugin. The panel
also carries a DNS lookup tester: resolve a name against the active
provider's own address with dig/nslookup, to confirm a switch took effect or
that a provider blocks a domain.

Co-authored-by: nightwatch75 <nightwatch75@users.noreply.github.com>
Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>

dns-switcher/dns-switcher.luau

@@ -0,0 +1,78 @@
+--!nonstrict
+-- dns-switcher — bar widget: renders the state published by the service
+-- entry (service.luau).
+--
+-- Click mapping is declared in plugin.toml's [widget.actions] (plugin_api >=
+-- 14), not hard-coded here, so the user can remap it from the bar's own
+-- gesture settings like any built-in widget:
+--   Left click    — panel-toggle nightwatch75/dns-switcher:panel
+--   Right click   — plugin nightwatch75/dns-switcher:service all apply default
+--   Scroll up/down — plugin nightwatch75/dns-switcher:service all cycle next/prev
+--
+-- No middle-click binding: every bar widget carries a built-in `middle`
+-- binding that opens its own settings, and that default is exactly what's
+-- wanted here.
+
+local STATE_KEY = "dns_state"
+local GLYPH_UNKNOWN = "globe"
+
+local snapshot = nil -- last state published by the service
+
+local function tr(key, args)
+    return noctalia.tr(key, args)
+end
+
+local function setLabel(text)
+    if noctalia.getConfig("show_label") == false then
+        barWidget.setText("")
+    else
+        barWidget.setText(text)
+    end
+end
+
+local function paint(glyph, role, label)
+    barWidget.setGlyph(glyph)
+    barWidget.setGlyphColor(role)
+    barWidget.setColor(role)
+    setLabel(label)
+end
+
+local function render()
+    local s = snapshot
+    if s == nil or (s.current == nil and s.error == nil) then
+        paint(GLYPH_UNKNOWN, "on_surface", tr("status_checking"))
+        barWidget.clearTooltip()
+        return
+    end
+    if s.changing == true then
+        paint("refresh", "secondary", tr("status_switching"))
+        barWidget.setTooltip(tr("tooltip_switching"))
+        return
+    end
+    if s.error ~= nil then
+        paint(GLYPH_UNKNOWN, "error", s.error)
+        barWidget.clearTooltip()
+        return
+    end
+    local role = s.current.id ~= "default" and "primary" or "on_surface"
+    paint(s.current.glyph, role, s.current.label)
+    local servers = s.current.ip
+    if servers == "" then
+        servers = s.servers ~= "" and s.servers or tr("status_auto")
+    end
+    barWidget.setTooltip({
+        { key = tr("tooltip_provider"), value = s.current.label },
+        { key = tr("tooltip_servers"), value = servers },
+        { key = tr("tooltip_actions"), value = tr("tooltip_hints") },
+    })
+end
+
+noctalia.state.watch(STATE_KEY, function(value)
+    if type(value) == "table" then
+        snapshot = value
+        render()
+    end
+end)
+
+snapshot = noctalia.state.get(STATE_KEY)
+render()