Add wrong-slot STF test with filler support

[bomanaps]

🗒️ Description

Add skip slot flag to state transition filler and implement consensus test rejecting blocks with mismatched slots.

🔗 Related Issues or PRs

#120

✅ Checklist

• Ran tox checks to avoid unnecessary CI fails:

  uvx tox

• Considered adding appropriate tests for the changes.
• Considered updating the online docs in the ./docs/ directory.

[tcoratger]

I think there is no change here, can we revert this to minimize git diff? I guess this is the same at other places in this PR :)

[bomanaps]

Sorry about this I got a Ruff’s line-length lint so had to split to a new line

[tcoratger]

Same comment about minimizing git diff

[tcoratger]

Same message about minimizing git diff

[tcoratger]

I'm not sure why we need all this here and why we need this new skip_slot_processing, looks like confusing and I guess we want to test the classical state_transition processing here because the block processing is the first step of it

leanSpec/src/lean_spec/subspecs/containers/state/state.py

Lines 521 to 522 in 715276e

	# First, process any intermediate slots.
	state = self.process_slots(block.slot)

so that we should see the exact same error that if we do state.process_block(block) because the only additional step which happens before this in the state transition processing is to check that valid_signatures is true but this is the case here in this call so there should be no problem.

[bomanaps]

The only reason the skip_slot_processing flag exists is to make the new “wrong slot” vector possible. state_transition() always advances through process_slots(block.slot) before running process_block, so by the time the header check runs the state slot already equals the block slot and assert block.slot == self.slot can never trip. The flag simply lets an individual test opt out of that automatic advancement so we can feed the block to process_block while the state is still at the earlier slot. Everything else continues through the normal state_transition path; no existing tests are touched. If you’d prefer an alternative hook (e.g., a dedicated helper to run process_block directly), I’m happy to rework it the key requirement is just some way to bypass that initial process_slots call for this negative test.

[tcoratger]

Ah yes true I get it, can you solve conflicts?

[tcoratger]

Hey @bomanaps I think that we have some conflicts with recent updates and then looks good, we should just try to minimize git diff here especially with the comments if possible.