Courses and workshops now have safer payment, access, and application workflows

Course payment choices are now clearly separated into pay in full, deposit with
one later balance, equal installments without a deposit, and deposit followed
by balance installments. Automatic card plans require an explicit buyer
authorization. When a scheduled card payment needs attention, the client gets
a secure link for that exact installment; they can confirm it or replace the
card without being charged the whole remaining balance.

The Sessions tab remains the single place to define what each payment stage
unlocks. Classes and workshops have independent selections, totals, dates,
cancellation windows, late-cancellation and no-show fees, allowance forfeiture,
and streaming/replay rights. Adding another linked date never books course
participants automatically; eligible participants choose it themselves.

Workshop Library streaming settings now support workshop-specific cameras,
online capacity, automatic start/end, recording, publication, retention, and
viewer access. Individual occurrences can still override those defaults.

Course and Workshop Library lists now use the familiar BookingBible layout on
desktop and responsive cards on smaller screens. Duplicate is available on
each row as well as in bulk actions. A duplicate is an isolated draft: it keeps
reusable payment/access or streaming configuration, while schedules,
participants, bookings, access consumption, and old pass links stay behind.

Editor failures now remain visible in a summary and move focus to the field
that needs attention. This also fixes the Sentry-reported save failure caused
by writing a blank custom-label value as SQL null into the non-null `labels`
column.

Application-gated courses can now collect applications from individuals or
companies. A company must provide its name and at least one proposed
participant name, with an optional note for each person. Admins review those
details from the roster; accepting an application grants eligibility without
automatically booking any sessions or creating fake client profiles.