refactor(part1): Consolidate simulate command.

[blmalone]

The simulate command right now looks something like:

Nested:

SIMULATE_WITHOUT_LEDGER=1 just --dotenv-path $(pwd)/.env --justfile ../../../nested.just simulate foundation

Single:

SIMULATE_FROM_LEDGER=1 just --dotenv-path $(pwd)/.env --justfile ../../../single.just simulate

this PR simplifies the command to be: Nested:

SIMULATE_WITHOUT_LEDGER=1 just simulate foundation

Single:

SIMULATE_FROM_LEDGER=1 just simulate

note: you'll still need to pass through the .env file if needed.

We can do this for other commands and eventually delete both single.just and nested.just.