chore: sync all pending changes — kirigami platform headers, cookbook fix, docs, patches

Kirigami: remove stub .cpp, add Qt platform integration headers for
QML gate. Matches KDE src/pattern for direct header-only builds.

Cookbook: add --no-backup-if-mismatch to patch invocation (fetch.rs).

Kernel: consolidate patch chain, add debug-scheme-serial-fix.

Docs: archive old audit reports, add CHANGELOG and hardware validation
matrix. Update AGENTS.md with Linux reference source policy.

Scripts: add test-network-qemu.sh, test-storage-qemu.sh.

.gitignore: add local/reference/ exclusion.

.gitignore

@@ -94,3 +94,4 @@ local/recipes/kde/kwin/**
 Packages/*.pkgar
 local/cache/pkgar/
 local/patches/base/redox.patch
+local/reference/