Add validate_transaction_template_limits as a post-consensus mempool admission
check. It rejects txs that cannot fit in a block template under the current
delayed mempool limits, before standardness-in-context and RBF eviction.

Use raw per-dimension limits for clearer errors: compute, transient, storage,
and gas. Keep mempool_block_mass_limits in Config alongside derived cofactors,
so selectors/RBF still use normalized weights while admission checks raw fit.

Clean standardness tests by removing stale mass/gas cases and decoupling relay
fee arithmetic from the removed standard mass constant. Extend Toccata tests to
cover delayed transient admission and gas rejection even when non-standard txs
are allowed.

base the standard relay fee floor on max(compute, transient) so transient block-space usage has a minimum cost, move fee check out of the loop so it's checked once and not per input and add context-standardness coverage for fee and input script checks.

Set the classic P2SH sigop standardness cap to match the previous 100k compute-mass allowance, and document why compute mass remains the real execution bound.

Remove the redundant is_unspendable branch from dust classification: standardness already rejects non-standard SPKs before dust, and standard SPK classes are spendable.

Drop the relay-fee dust threshold from mempool standardness and remove the mining dust helper. KIP9 storage mass already prices UTXO growth at the system level.

Use the real contextual storage mass calculation in Toccata mempool tests and
add a tiny-output case that rejects with RejectStorageMass after consensus
in-context validation.

Separate duplicate detection from isolation standardness and rename the local
standardness helpers to std_in_isolation/std_in_context. Reuse the same
transaction-id checks before and after consensus validation to make the
concurrency recheck semantics explicit.

Assert that mempool mass cofactors keep the same reference across activation, and document the selector assumption when using the post-activation reference.

Mechanically move transaction block-limit validation out of validate_and_insert_transaction into check_transaction_limits, and add focused tests for gas, compute, transient, and storage limit errors.
Keep the Toccata activation tests intact and document which pipeline checks should survive the post-fork cleanup.