Adds a light confirmation modal (DetailAccountWizard) that flips a simple
balance account to detailed entry mode: sets kind='detailed' and
detailed_since = today (local civil day, YYYY-MM-DD) via updateBalanceAccount.
Toggle-only — no title capture; per-security holdings are entered at the next
normal snapshot, where validateDetailedSnapshot requires them from the pivot on.
Entry point: a 'Détailler en titres' action in the per-row actions menu of
BalanceAccountsTable, shown only for kind==='simple' rows (replaces the disabled
'Détail / coming soon' placeholder). Past aggregated history stays frozen
read-only. The flip is one-way: the #212 service backstop rejects
detailed -> simple once holdings exist, and the UI exposes no inverse action.
Exports buildDetailToggleInput() as a pure helper for a focused unit test
(project has no jsdom harness). FR/EN i18n under balance.detailWizard.*; removed
the now-dead balance.overview.detailAction / detailComingSoon keys.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
