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/AutoFill.entitlements

@@ -0,0 +1,8 @@
+<?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>com.apple.developer.authentication-services.autofill-credential-provider</key>
+        <true/>
+    </dict>
+</plist>