Singleton value for the global IndexDimension::AnyPackageWrite marker:
every package write maps to the same key. Like EVENT_EXTANT_VALUE, it is
a single placeholder byte so the encoded key keeps the standard
[tag, value...] shape and passes BitmapKey::new’s length invariant.
Singleton value for the internal IndexDimension::EventExtant marker:
every real event maps to the same key. It carries a single placeholder byte
so the encoded row key has the standard [tag, value...] shape and passes
BitmapKey::new’s length invariant (dimension keys must be at least two
bytes) without a per-tag carve-out. The marker is a singleton — one row per
bucket, not per event — so the extra byte costs ~1 byte per bucket-row.
Singleton value for the internal IndexDimension::TxUniverse marker.
Like EVENT_EXTANT_VALUE, it is a single placeholder byte so the encoded
key has the standard [tag, value...] shape and passes BitmapKey::new’s
length invariant. The key never reaches storage — backends recognize the
tag at scan time and synthesize full buckets over the requested range.
Build an EventType compound value at the desired specificity.
instantiation_bcs is the BCS encoding of Vec<TypeTag>, used only
when matching a fully instantiated generic type.