- Rename AiPromptRules::promptRule() to wizardPromptRule() so the asymmetry is
explicit: only the create wizard carries a minimum; the editor's generation
reuses just the shared maximum.
- Add aria-live and a data-testid to the prompt counter so the over-limit state
is announced to assistive tech and reachable from browser tests.
The counter added earlier drifted from the backend in two ways: it counted
UTF-16 code units over the raw (untrimmed) value, while the backend measures
Unicode characters (mb_strlen) over the trimmed value that is actually sent —
so emoji or trailing whitespace could falsely turn the counter red and block
the button. The 2000 limit was also copied into three places, and the wizard's
frontend `>= 3` minimum had no backend counterpart.
- Add App\Support\AiPromptRules as the single source of truth for the prompt
bounds; both StartPostCreationRequest and GeneratePostContentRequest use it.
- Add min:3 to the create wizard endpoint so front and back agree (the editor's
generate-content flow keeps `required` — it has no counter to mirror).
- Count code points over the trimmed value in AiPostWizard so the counter and
the submit gate match what the backend validates, matching AltTextDialog.
- Cover min/max/boundary in PostAiCreateTest.
