Fixed Azure GPT-5.5+ completion requests failing when reasoning is enabled

Fixes

• DesktopReduced composer lag when drafts include large pasted images or attachments.
• DesktopLet project search match any known recent project instead of only the first five.@NumerousJLs
• DesktopCleared stale assistant errors from the timeline once the same turn resumes streaming.
• DesktopSkipped legacy config reads against v2 servers to avoid spurious config loading issues.@resetsix