feat(obsidian): add option to choose different note even when linked

Problem: When clicking on a burg/marker that already has a linked note,
it would automatically open that note without giving the user any choice.
Users need the ability to manually browse/search for a different note.

Solution: Show a dialog when a linked note is found with 3 options:
1. "Open Linked Note" - Open the currently linked note (default/fast path)
2. "Choose Different Note" - Browse/search for a different note to link
3. "Cancel" - Close the dialog

Benefits:
- Gives users full control over note selection
- Still makes the common case (opening linked note) fast and easy
- Allows re-linking burgs/markers to different notes
- Shows the path of the linked note before opening

This addresses the need to manually browse even when a note is already
linked, while preserving the fast instant-open behavior for linked notes.

modules/ui/obsidian-notes-editor.js

@@ -28,7 +28,9 @@ async function findOrCreateNote(elementId, elementType, coordinates) {
 
   if (note) {
     INFO && console.log("Found note by FMG ID:", note.path);
-    return note;
+    closeDialogs("#obsidianNoteLoading");
+    // Show dialog with option to open linked note or choose different one
+    return await showLinkedNoteDialog(note, elementId, elementType, coordinates);
   }
 
   // Find by coordinates
@@ -57,6 +59,46 @@ async function findOrCreateNote(elementId, elementType, coordinates) {
   return await showNoteSelectionDialog(matches, elementId, elementType, coordinates);
 }
 
+async function showLinkedNoteDialog(note, elementId, elementType, coordinates) {
+  return new Promise((resolve, reject) => {
+    alertMessage.innerHTML = `
+      <div style="padding: 1em;">
+        <p style="margin-bottom: 1em;"><strong>✓ Found linked note:</strong></p>
+        <div style="padding: 12px; background: #f0f8ff; border: 1px solid #0066cc; border-radius: 4px; margin-bottom: 1.5em;">
+          <div style="font-weight: bold; margin-bottom: 4px;">${note.name}</div>
+          <div style="font-size: 0.9em; color: #666;">Path: ${note.path}</div>
+        </div>
+        <p style="font-size: 0.9em; color: #666;">This element is already linked to the note above. You can open it or choose a different note.</p>
+      </div>
+    `;
+
+    $("#alert").dialog({
+      title: "Linked Note Found",
+      width: "500px",
+      buttons: {
+        "Open Linked Note": function () {
+          $(this).dialog("close");
+          resolve(note);
+        },
+        "Choose Different Note": async function () {
+          $(this).dialog("close");
+          try {
+            const differentNote = await promptCreateNewNote(elementId, elementType, coordinates);
+            resolve(differentNote);
+          } catch (error) {
+            reject(error);
+          }
+        },
+        Cancel: function () {
+          $(this).dialog("close");
+          reject(new Error("Cancelled"));
+        }
+      },
+      position: {my: "center", at: "center", of: "svg"}
+    });
+  });
+}
+
 function showLoadingDialog() {
   alertMessage.innerHTML = `
     <div style="text-align: center; padding: 2em;">