Revise README to reflect changes since v0.1#69

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jkaczman wants to merge 3 commits intomainfrom

Commits on Dec 21, 2025

docs(readme): simplify project intro and security note
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Commits on Dec 22, 2025

fix(deploy): remove jq/unzip/ssh/scp checks and expand Docker install guidance
jkaczman
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Commits on Apr 20, 2026

docs: preliminary readme revisions
jkaczman
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