Add last known good rendering of card in error state to stack item

[habdelra]

This PR adds the last known good rendering of a card in an error state for a stack item. In the case there is no last known good HTML, we'll show a generic message.

Note that this does not yet support live updates into and out of an error state. that will come in a subsequent PR.

This is the view for a card without a last known good state:

[github-actions]

Host Test Results

    1 files  ±0      1 suites  ±0   19m 59s ⏱️ +36s
688 tests +2  687 ✔️ +2  1 💤 ±0  0 ❌ ±0 
693 runs  +2  692 ✔️ +2  1 💤 ±0  0 ❌ ±0 

Results for commit af119a7. ± Comparison against base commit 9d3f8f8.

This pull request removes 2 and adds 4 tests. Note that renamed tests count towards both.

Chrome 131.0 ‑ Integration | operator-mode: a 403 from Web Appliction Firewall is handled gracefully when auto-saving
Chrome 131.0 ‑ Integration | operator-mode: opens workspace chooser after closing the only remainingcard on the stack

Chrome 131.0 ‑ Integration | operator-mode: a 403 from Web Application Firewall is handled gracefully when auto-saving
Chrome 131.0 ‑ Integration | operator-mode: it renders a card with an error that has a last known good state
Chrome 131.0 ‑ Integration | operator-mode: it renders a card with an error that has does not have a last known good state
Chrome 131.0 ‑ Integration | operator-mode: opens workspace chooser after closing the only remaining card on the stack

♻️ This comment has been updated with latest results.

[lukemelia]

Is it impossible to know what realm an error doc is from?

[habdelra]

Hmm, I’ll look into it. Presumably some realm is returning the error response. Perhaps it’s a header? If so we’ll have to refactor how the stack item calculates the realm, as right now I does so from a running card.

[lukemelia]

Maybe it makes sense for the error doc to carry the realm?

[habdelra]

Good idea

[habdelra]

addressed in 64e950c