Add node docs, collabora purple UI, and portable install env

Human-readable help in all six palette nodes, docs/NODES.md with usage examples, expanded example flows, and auto-detect NODERED_DIR plus CODE bridge IP from .env on any VM.

Co-authored-by: Cursor <cursoragent@cursor.com>

nodes/collabora-extract.html

@@ -1,7 +1,7 @@
 <script type="text/javascript">
     RED.nodes.registerType('collabora-extract', {
         category: 'nextcloud collabora',
-        color: '#0082c9',
+        color: '#7950a2',
         defaults: {
             name: { value: '' },
             config: { type: 'nc-collab-config', required: true },
@@ -32,6 +32,23 @@
 </script>
 
 <script type="text/html" data-help-name="collabora-extract">
-    <p><code>/cool/extract-document-structure</code></p>
-    <p>Ingång: <code>msg.ncPath</code> eller Buffer i <code>msg.payload</code>. Valfritt <code>msg.filter</code>.</p>
+    <p><strong>Lista vad som finns i dokumentet.</strong> Content controls, fält, ev. annan struktur beroende på filter. Returnerar JSON — ingen ny fil.</p>
+
+    <h4>Varifrån</h4>
+    <p>Samma som convert: <code>msg.payload</code> eller WebDAV GET <code>msg.ncPath</code>.</p>
+    <p>Filter: dropdown eller <code>msg.filter</code>. Default <code>contentcontrol</code>.</p>
+
+    <h4>Vart</h4>
+    <p>POST multipart → <code>/cool/extract-document-structure</code></p>
+
+    <h4>Ut</h4>
+    <p><code>msg.payload</code> och <code>msg.structure</code> = struktur-JSON</p>
+
+    <h4>När</h4>
+    <p>Innan du fyller en mall. Du får fältnamnen (Kund, Datum …) så nästa nod vet vad den ska slå in.</p>
+
+    <pre>inject { ncPath: "/Mallar/avtal.docx" }
+  → collabora-extract (filter: contentcontrol)
+  → function (mappa data till fältnamn)
+  → collabora-transform / nc-office / bridge fillTemplateSave</pre>
 </script>