## Summary
Phase 3.1 of the message-interpolation optimization series. Fixes 9 of the 28 sites flagged in the Phase 2 audit (PR #2435):
| File | Fix |
|---|---|
| `Commands/StaffAccess.cs:88,99` | Drop redundant `.ToString()` on enum holes |
| `Commands/Handlers.cs:102` | `builder.ToString()` -> `builder.AsSpan()` |
| `World Saves/SaveCommands.cs:71-75` | Merge 3 concatenated `$"..."` into one literal |
| `Server/Items/Item.cs:4213` | Hoist nested ternary `$"..."` to if/else |
| `Engines/Factions/Mobiles/Guards/BaseFactionGuard.cs:140-150` | Convert switch expression to switch statement |
| `Mobiles/Monsters/LBR/Jukas/JukaLord.cs:85` | Restructure `string.Format(toSay.RandomElement(), ...)` into switch |
| `Misc/AttackMessage.cs:30-41` | Inline `AggressorFormat`/`AggressedFormat` constants |
No functional changes. Each site emits identical text; the only difference is that the message string is now built into a pooled char buffer instead of being allocated as a `string` first.
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