chore: sync Windows RC recovery into v0.9.10

[numnx]

What changed

Syncs the final release-candidate reliability fixes from dev into release/v0.9.10:

• bounded recovery for the exact transient Windows NSIS 0xC0000005 termination
• direct Electron Builder invocation with explicit --publish never in artifact-only desktop diagnostics
• regression tests and canonical/public documentation

Validation

• dev PR fix: harden Windows installer smoke recovery #3151: full required matrix passed
• Release Candidate Diagnostics run 29512330109: Linux, macOS, and Windows all built, installed, launched, reached renderer/backend readiness, exited cleanly, and uploaded artifacts
• local focused backend tests: 20 passed
• local TypeScript, production build, script syntax, and docs synchronization passed

Risk / rollback

Low risk and release-focused. Retry behavior remains restricted to the exact observed Windows access-violation code; diagnostic workflows remain artifact-only. Revert this sync PR to remove the release-branch delta.