Phase 3 status

Phase 3 is complete.

Exit condition	Evidence	Status
Steam root and library parsing	Bounded KeyValues fixture tests	Passed
App-manifest parsing	Installed, partial, malformed, oversized, and invalid-UTF-8 fixtures	Passed
Normalized identity	Stable `steam:<appid>` and deterministic installation UUID tests	Passed
Read-only provider surface	Discovery/info-only capability and unsupported-launch tests	Passed
CLI integration	Provider-scoped list, search, info, and scan test	Passed
Real-system acceptance	Local Steam metadata scan, no client start or game launch	Passed
Repository gates	`make check`	Passed

Steam launch-plan generation, client startup, Proton behavior, and lifecycle tracking remain Phase 4 work.