install.ps1 set ServicePointManager's certificate callback to a
PowerShell scriptblock. ServicePointManager can invoke that callback on
a worker thread that has no runspace, where a scriptblock delegate
fails closed, so agent downloads died with a TLS error even though the
certificate policy would have accepted them (hit by an rc.6 tester with
Skip TLS verification enabled). The copied install command already
migrated to a compiled validator for exactly this reason in rc.6; the
downloaded script now does the same. Validation policy is unchanged,
with fingerprint pinning first, then insecure, then clean chains, then
the custom CA. Verified with pwsh covering all four policy branches
plus the callback running on a runspace-free worker thread.
Contract-Neutral: installer TLS callback implementation moved to a compiled type; same validation policy, no payload or endpoint change
Use the installer-owned ProgramData directory consistently for token lookup, enrollment state, agent identity, receipts, and service runtime data. Pass that directory explicitly to the Windows service and retain the existing Linux default elsewhere.
Contract-Neutral: Windows agent state-path alignment preserves the existing installer and agent public contract
Contract-Neutral: Legacy Windows PowerShell TLS enum compatibility preserves the existing installer transport contract without changing its public interface
Tighten v5-to-v6 upgrade safety, release installability, provider MSP mode handling, AI cost accounting, metrics flushing, and frontend guardrails for the v6.0.0 GA candidate.
