Add plasmoid scaffold: metadata.json + config schema

Plasma/Applet package metadata (tray applet, id sk.houmeres.synologynas)
and the KConfigXT schema (hosts JSON, mount root, SMB version, options).
Passwords are never stored in config — they live in KWallet.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

package/contents/config/main.xml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<kcfg xmlns="http://www.kde.org/standards/kcfg/1.0"
+      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+      xsi:schemaLocation="http://www.kde.org/standards/kcfg/1.0
+                          http://www.kde.org/standards/kcfg/1.0/kcfg.xsd">
+    <kcfgfile name=""/>
+    <group name="General">
+        <!-- JSON array of host objects:
+             {id, label, host, username, domain, mountRoot, vers}
+             Passwords are NEVER stored here; they live in KWallet. -->
+        <entry name="hosts" type="String">
+            <default>[]</default>
+        </entry>
+        <!-- Empty => resolved at runtime to <home>/NAS -->
+        <entry name="defaultMountRoot" type="String">
+            <default></default>
+        </entry>
+        <!-- SMB dialect passed to mount.cifs (vers=). -->
+        <entry name="smbVersion" type="String">
+            <default>3.1.1</default>
+        </entry>
+        <!-- Extra comma-separated mount.cifs options. -->
+        <entry name="mountOptions" type="String">
+            <default>iocharset=utf8</default>
+        </entry>
+        <entry name="fileMode" type="String">
+            <default>0700</default>
+        </entry>
+        <entry name="dirMode" type="String">
+            <default>0700</default>
+        </entry>
+    </group>
+</kcfg>