linking: Make rescan optional on linkable changes

Split rescan-on-linkable triggering into a separate script file
(linking/rescan-on-linkable.lua) that can be disabled via
wireplumber.profiles by setting hooks.linking.rescan-on-linkable =
disabled.

src/config/wireplumber.conf

@@ -656,6 +656,11 @@ wireplumber.components = [
     name = linking/rescan.lua, type = script/lua
     provides = hooks.linking.rescan
   }
+  {
+    name = linking/rescan-on-linkable.lua, type = script/lua
+    provides = hooks.linking.rescan-on-linkable
+    requires = [ hooks.linking.rescan ]
+  }
   {
     name = linking/find-media-role-target.lua, type = script/lua
     provides = hooks.linking.target.find-media-role
@@ -709,7 +714,8 @@ wireplumber.components = [
     requires = [ hooks.linking.rescan,
                  hooks.linking.target.prepare-link,
                  hooks.linking.target.link ]
-    wants = [ hooks.linking.target.find-media-role,
+    wants = [ hooks.linking.rescan-on-linkable,
+              hooks.linking.target.find-media-role,
               hooks.linking.target.find-defined,
               hooks.linking.target.find-audio-group,
               hooks.linking.target.find-filter,

src/scripts/linking/rescan-on-linkable.lua

@@ -0,0 +1,25 @@
+-- WirePlumber
+--
+-- Copyright © 2026 Axis Communications AB.
+--
+-- SPDX-License-Identifier: MIT
+--
+-- Trigger a full rescan when linkable session items are added or removed.
+-- This can be disabled by setting hooks.linking.rescan-on-linkable = disabled
+-- in wireplumber.profiles.
+
+log = Log.open_topic ("s-linking")
+
+SimpleEventHook {
+  name = "linking/rescan-trigger-on-linkable-added-removed",
+  interests = {
+    EventInterest {
+      Constraint { "event.type", "c", "session-item-added", "session-item-removed" },
+      Constraint { "event.session-item.interface", "=", "linkable" },
+    },
+  },
+  execute = function (event)
+    local source = event:get_source ()
+    source:call ("schedule-rescan", "linking")
+  end
+}:register ()

src/scripts/linking/rescan.lua

@@ -218,11 +218,6 @@ SimpleEventHook {
 SimpleEventHook {
   name = "linking/rescan-trigger",
   interests = {
-    -- on linkable added or removed, where linkable is adapter or plain node
-    EventInterest {
-      Constraint { "event.type", "c", "session-item-added", "session-item-removed" },
-      Constraint { "event.session-item.interface", "=", "linkable" },
-    },
     -- on device Routes changed
     EventInterest {
       Constraint { "event.type", "=", "device-params-changed" },