chore: add .yamllint configuration

[UserMandhapati]

Added a .yamllint file to enforce consistent formatting and syntax rules for all YAML configuration files in the repository.

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Note

Low Risk
Low risk: adds lint configuration only and does not affect runtime code paths.

Overview
Introduces a new .yamllint config extending the default ruleset and setting consistent YAML style checks (120-char line length, 2-space indentation, and restricted truthy values).

^{Written by Cursor Bugbot for commit a48c6ae. This will update automatically on new commits. Configure here.}