complete codex docs

docs/decisions/0002-status-detection.md

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+# Decision 0002: Agent-Truthed Status Detection
+
+## Status
+
+Accepted
+
+## Decision
+
+Server status should be derived from agent truth:
+
+1. managed process/session existence
+2. required game port listening
+3. optional query and metadata lookup
+
+## Reasoning
+
+- Marker files become stale after crashes, failed starts, and power loss.
+- Query systems like LGSL and GameQ are useful but unreliable as the sole online signal.
+- The agent can check the actual runtime state locally.
+
+## Alternatives Considered
+
+- query-only status
+- marker-file status
+- process-only status
+
+## Why Those Were Not Chosen
+
+- Query-only status can lie for supported games.
+- Marker files are not authoritative.
+- Process-only status misses the important readiness condition: the port must actually listen.
+