chore(deps): allowlist rete engine + @lit/context (dep-drift gate)

The Phase 36/37 Rete port (FlowCanvas) and the Lit target/runtime added
rete, rete-area-plugin, rete-connection-plugin, rete-render-utils, and
@lit/context as direct deps but never re-snapshotted the supply-chain
allowlist, leaving the Dependency Drift gate red on main since 2026-06-09.
All five are legitimate declared dependencies; re-snapshot the allowlist.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: serpentblade

scripts/dep-allowlist.txt

@@ -328,6 +328,7 @@
 @lezer/yaml
 @lit-labs/preact-signals
 @lit-labs/ssr-dom-shim
+@lit/context
 @lit/reactive-element
 @lmdb/lmdb-darwin-arm64
 @lmdb/lmdb-darwin-x64
@@ -1348,6 +1349,10 @@ resolve-pkg-maps
 resolve-protobuf-schema
 resolve-url-loader
 restore-cursor
+rete
+rete-area-plugin
+rete-connection-plugin
+rete-render-utils
 retext
 retext-latin
 retext-smartypants