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.

src/cook/fetch.rs

@@ -1166,6 +1166,7 @@ pub(crate) fn fetch_apply_patches(
             command.arg("--strip=1");
             command.arg("--batch");
             command.arg("--fuzz=0");
+            command.arg("--no-backup-if-mismatch");
             run_command_stdin(command, patch_data.as_slice(), logger)
                 .map_err(|e| format!("patch {patch_name} FAILED: {e}"))?;