chore: rename autofill target/folder to AutoFill

Also drops the stray empty AutoFillExtension/ directory left over from
an earlier abandoned attempt at creating this target, and cleans up
duplicate/stale scheme entries in xcschememanagement.plist.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WYqycDFsynHH9VnnK7LNSf

AutoFill/Info.plist

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>NSExtension</key>
+	<dict>
+		<key>NSExtensionMainStoryboard</key>
+		<string>MainInterface</string>
+		<key>NSExtensionPointIdentifier</key>
+		<string>com.apple.authentication-services-credential-provider-ui</string>
+	</dict>
+</dict>
+</plist>