[feat] Add lambda-invoke CLI for local + remote invocation

[manojmahapatra]

Describe the feature

Add a small CLI (lambda-invoke) that can invoke a Lambda function locally (via /invoke) or remotely (via AWS CLI). This mirrors Cargo Lambda’s invoke and improves the developer feedback loop.

• Local testing today requires manual curl to http://127.0.0.1:7000/invoke
• Remote testing requires aws lambda invoke commands

Inspiration

Cargo Lambda's invoke provides a simple loop. We can match that experience here with a low-risk change.

Use Case

1. Developers run their function locally and invoke it with a single command instead of using curl requests.
2. It can be used for remote smoke tests post deployment.
3. CI can invoke a local and remote function using a simple CLI.

Proposed Solution

No response

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

[manojmahapatra]

@sebsto Not urgent, but let me know what do you think on this (as in an additive feature).

[sebsto]

Thank you Manoj for this proposal.
I would suggest to add this in the new plugin design document instead of considering this as a separate feature request.

My plan is to resume work on the new plugin this week and try to land it before end of Q1.

Looking at the doc, I realise it's already in there for a phase 2:

We may consider additional plugins in a future release. For example, we could consider a plugin to help developers invoke their Lambda function (lambda-invoke) or to monitor CloudWatch logs (lambda-logs).

I will close this one as a duplicate / addition to #566 and #567