complete codex docs

docs/decisions/0006-installers.md

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+# Decision 0006: Installers Must Be Game-Capability Driven
+
+## Status
+
+Accepted
+
+## Decision
+
+Installer behavior should be driven by game XML capabilities and module metadata instead of ad hoc shell scripts or one-off module pages.
+
+## Reasoning
+
+- Different games need different install strategies.
+- Some games are content-copy based.
+- Some are SteamCMD based.
+- Some need key copying, startup parameter edits, or profile transforms.
+- The Panel needs a structured model to support all of them cleanly.
+
+## Alternatives Considered
+
+- per-game custom shell scripts only
+- raw customer-provided installer commands
+
+## Why Those Were Not Chosen
+
+- They are harder to secure and harder to document.
+- They do not scale cleanly across games or platforms.
+