fix(browser): preserve unknown script ownership through reconciliation

docs/javascript-runtime-reconciliation.md

@@ -144,6 +144,10 @@ Script inventory completeness remains a separate reported fact. Unavailable,
 truncated, or attach-limited worker inventory prevents negative code-presence
 claims even when the selected page's script inventory is complete. Accepted
 positive script correspondences remain loaded.
+An Electron script's explicit unknown `frame_scope` preserves its reported
+frame ID and sourceURL provenance as node properties, but does not link that
+script to the current frame inventory. Attach-limited script coverage cannot
+establish negative code-presence claims.
 
 None of these states proves feature execution, initialization order,
 reachability, or causality. In particular, `not-observed-in-capture` never means