…s collection

Keeps base Posts collection from accruing condition-specific fixtures.

Cleaner than matching against a magic title string.

…n.condition

Previously only the render call was gated on passesCondition; the switch
still ran filterOptions resolves (DB queries on relationship/upload),
blocks validation, and full recursion into hidden subtrees. Add an
early-exit guard so a failing condition writes a minimal state entry and
returns, skipping access checks, validation, switch processing,
filterOptions, and child iteration. The client re-requests form state on
condition flips, so the minimal entry is sufficient.

…rendering-conditions-3x

Mirror the early-exit guard from perf/server-component-rendering-conditions:

- Preserve value/initialValue on the minimal state entry so the client can
  surface field values when conditions flip back to true without waiting on
  another round-trip.
- Drop the now-redundant `passesCondition === false` write inside the tabs
  branch. The early-exit captures that case before reaching this branch, so
  the inner conditional is unreachable.
- Match comment wording with the conditions branch for cleaner cross-branch
  diffs.

The short-circuit at the top of addFieldStatePromise skips the tab
branch when passesCondition is false, but the tab branch is where
state[field.id] gets written, and the Tabs component on the client
reads tab visibility from that key. Without the write, hidden tabs
fall back to passesCondition ?? true and render visible.

Mirror the state[field.id] write in the short-circuit so tabs that
fail their admin.condition pick up the --hidden class as expected.

The previous fix mirrored the state[field.id] write inside the
short-circuit, which required developers to remember that tab fields
have a dual-keyed state contract (state[path] AND state[field.id]).

Move that responsibility back to where it belongs — the tab branch —
and exclude tab from the short-circuit. The tab branch now:

- Uses the incoming passesCondition resolved by iterateFields instead
  of re-evaluating field.admin.condition.
- Writes state[field.id] unconditionally.
- Returns early when the tab is hidden, skipping recursion into
  descendants (matches the short-circuit's intent without duplicating
  its body).

Net effect is the same perf win with one tab-specific concern living in
one place.

Reorganize the tab branch so the flow reads linearly:

1. Strip-unselected check (return if not selected).
2. Write state[field.id] (the visibility marker the Tabs component reads).
3. Return early if the tab is hidden — no recursion needed.
4. Resolve child permissions and select scope.
5. Recurse into children.

Previously the permissions/select setup ran before the hidden-tab early
return, which was wasted work and obscured the control flow.

When a tab fails its admin.condition, the tab branch writes
state[field.id] but skips recursion into descendants. If the tab later
flips visible (or the tab itself was first surfaced after a previously
hidden ancestor became visible), the server rebuilds state and writes a
fresh state[field.id]. Without the addedByServer flag,
mergeServerFormState skips brand-new entries that aren't already on the
client, leaving the Tabs component reading a stale (or missing) value
and rendering the tab with the wrong visibility.

Mirror the addedByServer logic used for non-tab fields so newly minted
tab entries actually reach the client.