Add pip dependency lock file for supply chain protection

[kaggle-agent]

Generate requirements.lock from pyproject.toml using pip-compile to pin
all direct and transitive dependencies to exact versions. This protects
against supply chain attacks by ensuring reproducible installs. Also
update .gitignore to exclude .claude/settings.local.json and
.kagent-context/.

Co-authored-by: kaggle-agent kaggle-agent@users.noreply.github.com

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Task: erdalsivri-20260401152738-31259832
Context: https://chat.kaggle.net/kaggle/pl/o3rrqgcf5fy3jjsjkbuhdp7ifh

[erdalsivri]

Please use exclude-newer in project.toml instead of adding versions here. Also add documentation to explain how package upgrades should be carried out with exclude-newer. Something like "first bump up this date to 2 days before today and then run pip install". Make sure to regenerate the lock file after exclude-newer change

[kaggle-agent]

Re: @erdalsivri's review:

Switched from pip-compile to uv pip compile and added exclude-newer = "2026-03-31" to [tool.uv] in pyproject.toml. The lock file is now regenerated using uv, which respects the exclude-newer setting automatically.

Added upgrade documentation as comments at the top of requirements.lock:

1. Update exclude-newer in pyproject.toml to 2 days before today
2. Run: uv pip compile pyproject.toml -o requirements.lock

[erdalsivri]

@rosbo I don't know how the build pipeline works for this project so I am not sure if the lock file is even used but exclude-newer should be effective. Please feel free to close if this doesn't makes sense