### Summary
`default-flags.json` was never shipped — `Configuration/` is gitignored — so the predefined-flag loader has been dead since #2328. A fresh shard boots with 0 flags and writes no JSON until an admin changes something, so `[FeatureList` is empty on first run.
Stock flags are now defined in code. `Initialize()` runs `Load()` first, then `LoadDefaultFlags()` seeds any of the 14 stock keys the save is missing, reading each default from the static it syncs (`ServerFeatureFlags` / `ContentFeatureFlags`) rather than a duplicated boolean — so `speedhack_detection` stays off and `insurance` honors `Insurance.Configure` (`insurance.enable`). Existing entries are never overwritten, so admin state survives upgrades and saves predating a flag pick it up. `Save()` runs only when something was seeded, so all five JSON files exist from first boot.
Verified: `dotnet build Projects/UOContent/UOContent.csproj -c Release`, 0 warnings 0 errors.
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