feat: parameterize configuration

[ianlewis]

Allow setting the namespace selector, target environment variable, termination grace period, and debounce period via environment variables or flags.

Fixes #2

[Copilot]

Pull request overview

This PR parameterizes the reloader configuration by allowing the namespace selector, target environment variable, termination grace period, and debounce period to be set via environment variables or command-line flags. Previously, these settings were hardcoded or only available through environment variables.

Key changes:

• Introduced a ProcessManagerConfig struct to hold all configuration parameters
• Replaced hardcoded constants with configurable flags and environment variables with defaults
• Refactored the run function to accept a configuration object instead of individual parameters

Reviewed changes

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

File	Description
main.go	Added flag parsing for configuration parameters, helper functions for reading environment variables with defaults, and copyright header
reloader.go	Introduced ProcessManagerConfig struct, refactored ProcessManager to use configuration, updated UpdateNamespaces to accept a slice instead of a string, and added copyright header
reloader_test.go	Updated test to use new ProcessManagerConfig struct instead of environment variables and added copyright header

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[Ladicle]

Could you please update README.md as well?

[ianlewis]

Could you please update README.md as well?

Done. I left the note about the -- separator because the Go flag package will handle this. Flags after the -- are returned in flagset.Args()

[Ladicle]

LG!