feat(forge test): add an option to continue fuzzing run on assertion failure

[forkforkdog]

Component

Forge

Describe the feature you would like

Description:
Currently, Foundry’s invariant tests stop execution upon encountering the first assertion failure, ending the entire fuzzing campaign.

Feature Request:
Add an option to allow the fuzzing campaign to continue running until all configured runs are completed, even if assertion failures are encountered.

Rationale:
This feature would enable continuous fuzzing in an "Echidna-style" manner, where failing assertions are collected throughout the run without interrupting the campaign. Certain assertion failures require long-running fuzzing campaigns (e.g., 4+ hours), and stopping on the first failure can hinder the discovery of additional issues.

Expected Behavior:
When the continuous_run option is enabled, the fuzzer should:

1. Continue running despite encountering assertion failures.

2. Log all failures encountered during the campaign.

3. Upon manual cancellation (e.g., CTRL+C/CMD+C) or completion of the configured runs/timeout, present all call traces for reproducing the assertion failures.

Example Configuration:

[invariant]
continuous_run = true

Example Output:

test/fuzzing/FuzzPositions.sol:FuzzPositions                                     
    ↪ invariant_GLOB_01: [9/4294967295] Runs  
    ❌ Failures: 2

Additional context

No response