[xvcezrqpbxtpzblrt]

Problem

Every start opened the Models page on a screen that was not true:

• "Set up Strata / Connect engine" — for a computer that has the engine and a model;
• "this installation reports no supported graphics card" — for a PC with an RTX card.

A few seconds later the page jumped to the installed model. The cause is in the host: its first snapshot says available: false with the sentence "Connect a local Strata installation" before it has read anything, and the first read of the installation can take many seconds (measured here: the first /api/native answer came after about 30 s on a cold start). The page could not tell "not read yet" from "nothing installed", so it rendered the setup state.

Result

• The host's snapshot says checking: true until the first look at the installation ends; available: false before that no longer claims "nothing is installed".
• The last good snapshot is written to native-snapshot.json (only when it changes) and loaded at the next start, so the page opens on the models this computer already has while the fresh read runs behind it. A model deleted outside Strata disappears when that read ends.
• The Models page: with a known snapshot it renders at once; without one it says "Loading your models and settings…" instead of offering setup; the setup card appears only when the host is really offline or the read says there is no engine.

Validation

• Before: a poll of /api/native right after start returned nothing for 30 s, and the Models page showed the setup card for that time.
• Without a cache (first start after install): the page shows "正在加载模型和设置…" from the first frame, never the setup card, until the read ends. Screen captured.
• With the cache (next start): the Models page shows "Swift IQ3_XXS 已下载" at the first check, and the context/KV settle to 512K / K8V4 as the stored settings are applied. Screen captured.
• npm run typecheck clean; node --test tests/packaged-control.test.mjs tests/ui4-fixes.test.mjs → 33 pass, 0 fail.

Limits

• The cached snapshot is a few seconds old at most on a normal start; a model deleted while Strata was closed is shown briefly and then removed by the read.
• The first run after a fresh install has no cache: it shows the loading line for as long as the first read takes (about 6 s warm, 30 s cold on this PC). Shortening that read is a separate change.
• Only the Models page is gated; other screens still update their own native figures when the read ends.

[xvcezrqpbxtpzblrt]

Superseded by #4606, which carries this change with the rest of the 0.2.7 branch. Closing so the review has one place.