Two reliability bugs in the natural-language date input:
1. Clicking Edit on a saved-date pill and changing the value immediately
re-showed the saved value. clearAndEdit pre-fills the input with the
formatted saved date so the admin doesn't start over, but chrono
parses that string on the very first keystroke, re-sets parsedDate,
and the auto-hide template flips the pill back. Added an isEditing
flag that keeps the input visible across re-parses and clears on
blur once we have a valid parse.
2. Typing "tomorrow at 2pm" sometimes committed "tomorrow at <current
time>". UInput's template spreads \$attrs onto the inner <input>
alongside its own @input="onInput", and Vue's listener-array merge
intermittently drops the fall-through @input mid-typing — in the
reproduction, the final 'm' never reached parseNaturalInput, so
chrono's last successful read was "tomorrow at 2p" matching just
"tomorrow". Switched to @update:model-value (a declared emit on
UInput, so it goes through the reliable component-emit path) and
made onBlur always re-parse the final value as a backup.