Release exp-v0.52.294: add GLM-5.3 Flash to Z.AI catalog (#7323) (#7517)

Co-authored-by: n <a@n>

CHANGELOG.md

@@ -613,6 +613,8 @@
 
 ### Added
 
+- **GLM-5.3 Flash (`zai/glm-5.3-flash`) is now selectable in the Z.AI model list.** Z.ai's fast/cheap native-multimodal sibling of GLM-5.3 is added to the direct Z.AI catalog and the provider fallback list, following the same base-then-flash convention as the other GLM entries and inheriting the ≥5.2 reasoning-effort ladder. The onboarding default deliberately stays GLM-5.1. Thanks @rh-id. (#7323)
+
 - **Extensions can register a native "Configure" entry point under Settings → Extensions → Installed.** For complex editors that don't fit scalar `settings_schema` fields, a boot-trusted extension can call `ext.settings.registerConfigure(handler)` on the E0 handle to add one native Configure button for its current effective-enabled Installed row, while keeping the editor UI, validation, state, and persistence fully extension-owned. Registration is trust-gated and quarantine-aware, the first handler per extension wins (duplicates return `null`), and it returns an idempotent unregister; the button never appears in Diagnostics and is removed immediately on disable/uninstall. Thanks @franksong2702. (#7111)
 
 - **Each settled assistant turn's footer now shows the model that actually served it.** In transparent-stream mode the turn footer gains a compact model chip (e.g. `8s · claude-opus-4-8 · TTFT 640ms · …`), read *after* the turn completes so a mid-turn fallback shows the real model that answered rather than the one originally requested. The label renders exactly once per turn — a gateway/failover turn keeps its existing routing chip and the additive chip is suppressed — and the footer wraps gracefully at narrow widths and on mobile instead of stretching. The used-model is persisted with the session so it survives a reload. Thanks @franksong2702. (#6113, #6068)