docs(gui): client plugin loading RFC — final-state rewrite, bilingual pair

The loading-chain RFC (2026-07-23-client-plugin-loading-model, en/zh)
states the shipped model in its final form: two package kinds (dshClient
means plugin), one module system + one plugin governor, the end-to-end
loading flow, and hot reload with its support boundary — written for a
first-time reader, no intermediate-design narration. The two 2026-07-19
GUI RFCs defer their loading-chain sections to it and drop stale
vocabulary. config-catalog regenerated for the package rename; pairing
manifest tracks the renamed pair.

scripts/translation-pairing.manifest.json

@@ -6,6 +6,7 @@
     ".agents/notes/implemented/architecture/2026-07-19-gui-layering-and-rpc-protocol.md",
     ".agents/notes/implemented/architecture/2026-07-19-gui-web-client-architecture.md",
     ".agents/notes/implemented/architecture/2026-07-22-slot-type-chain-implementation.md",
+    ".agents/notes/implemented/architecture/2026-07-23-client-plugin-loading-model.md",
     ".agents/notes/implemented/process/2026-07-02-bilingual-docs-and-pairing-gate.md",
     ".agents/notes/implemented/process/2026-07-19-web-styling-system.md",
     "README.md",