ci: add basic CI pipeline for tests and linting

[GaneshPatil7517]

Summary

This PR introduces a minimal GitHub Actions CI pipeline for concore. It adds automated linting and test execution on every push and pull request.

What's included

• Python 3.11 setup with pip caching
• Dependency installation from requirements.txt
• Linting with ruff (syntax errors, invalid print, undefined all)
• Test execution with pytest
• Dockerfile.py build validation

Configuration notes

The following directories are excluded from linting/testing due to config-dependent experimental scripts:

• measurements/ - benchmark scripts requiring external port configuration
• 0mq/ - ZeroMQ examples with external variable definitions
• ratc/ - experimental code with known issues
• linktest/ - symlink files, not Python code
• Dockerfile.* - Docker files with .py extension

Why this matters

• Prevents broken code from being merged
• Catches syntax errors and import issues early
• Improves contributor feedback loop
• Establishes foundation for future test coverage

Verification

• Linting passes locally (ruff check .)
• Pytest runs without collection errors
• Existing draft-pdf.yml workflow is unchanged

Fixes #232

[Copilot]

Pull request overview

Adds a new GitHub Actions workflow to provide basic continuous integration for the repo (linting, pytest invocation, and a Dockerfile build check) on pushes and pull requests to the main branches.

Changes:

• Introduces .github/workflows/ci.yml to run Ruff checks for a small set of syntax/critical errors.
• Runs pytest with several directories ignored.
• Validates Dockerfile.py by attempting a docker build.

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[pradeeban]

@GaneshPatil7517 I see you are creating PRs against the main branch. Please create those against the dev branch. In this case, I was able to switch the branch to dev. Developing against the dev branch will ensure there is no repeated effort on an already fixed issue.

[GaneshPatil7517]

Hi @pradeeban, thanks for the heads up! I've updated the PR base branch to dev. I also added dev to the CI workflow triggers so it runs on pushes and PRs to dev as well. Let me know if anything else needs to be adjusted.

[pradeeban]

Merged. Thanks.