feat: add regex pattern field on inputs

[RothAndrew]

Description

Add pattern field for inputs, so that inputs can be checked against a regex

Related Issue

Relates to #190

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other (security config, docs update, etc)

Checklist before merging

• Test, docs, adr added or updated as needed
• Contributor Guide Steps followed

[RothAndrew]

First commit is just the tests TDD-style. Working on the PR now. Will drop another note if I need to set it down so somebody else can pick it up if they want to.

[Copilot]

Pull Request Overview

This PR introduces a new field, pattern, for input validation using regex on input fields. It adds a new test task in the YAML file and updates the end-to-end tests to verify both valid and invalid regex inputs.

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
src/test/tasks/inputs/tasks-with-inputs.yaml	Added a test task "input-with-regex" with regex-based validations
src/test/e2e/runner_inputs_test.go	Added end-to-end tests for validating regex-based input behavior

[RothAndrew]

Putting this aside since there is resistance to the idea. Putting forth my vote to do this (and whatever else needs to be done so that inputs has feature parity with variables) and then completely eliminate variables from Maru.