Follow up #2199 and #2183. Replace invalid cross-process WM_PRINT DC delivery with PrintWindow in one owned, deadline- and memory-bounded helper. Return metadata summaries by default through MCP with explicit retained image reads.
Verified actual pixels through CLI and MCP on Windows x64, including a non-elevated desktop, live redraws, PNG capacity refusal and retry, and target identity rejection. Final expanded acceptance and CI results are recorded in the pull request.