Add Quick Look Preview and Thumbnail extensions for .casera files

- Add CaseraQLPreview extension to show custom preview with contractor
  details and import instructions when viewing .casera files
- Add CaseraQLThumbnail extension to display teal icon in Messages
  and Files app instead of generic white box
- Update UTExportedTypeDeclarations to conform to public.content
  for better system file type recognition

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

iosApp/CaseraQLPreview/Base.lproj/MainInterface.storyboard

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<document type="com.apple.InterfaceBuilder3.CocoaTouch.Storyboard.XIB" version="3.0" toolsVersion="22505" targetRuntime="iOS.CocoaTouch" propertyAccessControl="none" useAutolayout="YES" useTraitCollections="YES" useSafeAreas="YES" colorMatched="YES" initialViewController="M4Y-Lb-cyx">
+    <device id="retina6_12" orientation="portrait" appearance="light"/>
+    <dependencies>
+        <plugIn identifier="com.apple.InterfaceBuilder.IBCocoaTouchPlugin" version="22504"/>
+        <capability name="Safe area layout guides" minToolsVersion="9.0"/>
+        <capability name="documents saved in the Xcode 8 format" minToolsVersion="8.0"/>
+    </dependencies>
+    <scenes>
+        <!--Preview View Controller-->
+        <scene sceneID="cwh-vc-ff4">
+            <objects>
+                <viewController id="M4Y-Lb-cyx" customClass="PreviewViewController" customModule="CaseraQLPreview" customModuleProvider="target" sceneMemberID="viewController">
+                    <view key="view" contentMode="scaleToFill" id="S3S-Oj-5AN">
+                        <rect key="frame" x="0.0" y="0.0" width="393" height="852"/>
+                        <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
+                        <viewLayoutGuide key="safeArea" id="bzV-dz-m25"/>
+                        <color key="backgroundColor" systemColor="systemBackgroundColor"/>
+                    </view>
+                    <extendedEdge key="edgesForExtendedLayout"/>
+                </viewController>
+                <placeholder placeholderIdentifier="IBFirstResponder" id="vXp-U4-Rya" userLabel="First Responder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="705" y="299"/>
+        </scene>
+    </scenes>
+</document>