[Bugs] editor: HUD note rows stay visible while shortcuts are collapsed

[Aymericr]

What does this PR do?

Editor-side fix for part of private-editor #1099.

HUD note rows always show (packages/editor/src/components/ui/helpers/contextual-helper-panel.tsx)

• A ! row in the contextual HUD (the corner-window note, e.g. "No wall meets here") explains why something won't happen; it isn't a key to press. The collapsed HUD used to keep only the first row plus active rows, so the note got folded under More shortcuts and the user never saw why the window wouldn't wrap the corner. Note rows are now always part of the collapsed set.
• More shortcuts now appears only when collapsing actually hides a row. Before, it showed whenever there was more than one action hint, even if expanding would reveal nothing new.
• Two tests in helper-manager.test.tsx cover both rules, using the real cornerHintRows('free_end') rows.

Viewer test isolation (packages/viewer/src/components/viewer/render-error.test.tsx)

• The frame-error test put back window/document by assigning their saved value. Under Bun that value is undefined, so the globals stayed defined as undefined and a later file's 'window' in globalThis check would think a window exists. The test now deletes the keys when they were absent before.

Not in this PR: the other two items in #1099 (wall presets no longer auto-armed when the Build tab opens in apps/editor/components/build-tab.tsx, and the duplicate project_ key) are not on this branch. build-tab.tsx still arms the first build tool on open.

How to test

1. Open the editor, start placing a window, and hover a free wall end. The HUD shows "No wall meets here" while collapsed, without expanding More shortcuts.
2. In a tool whose HUD has only a primary action plus a note row, More shortcuts is absent.
3. bun test packages/editor/src/components/ui/helpers/helper-manager.test.tsx: 7 pass.

Ran locally: bun run check-types (13/13 tasks pass) and bun run test. The test run has one failure, floor-foundation-support.test.ts › "a drag of -0.02 m lands on release". It fails the same way on origin/main, passes when run alone, and is unrelated to this diff.

Screenshots / screen recording

Not added yet.

Checklist

• I've tested this locally with bun dev
• My code follows the existing code style (run bun check to verify)
• I've updated relevant documentation (if applicable)
• This PR targets the main branch

  

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Note

Low Risk
UI-only HUD collapse rules plus test teardown; no auth, data, or runtime product paths beyond helper panel display.

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