[noderaven]

Release 1.6.10: five fixes from an outside review of 1.6.9, and a staged install.

An outside review of 1.6.9 found five defects and reproduced each with an offline script against the built helpers; all five reproduced again here before the fixes and were traced in the code.

• Doctor split the manifest's python into shell words (shlex.split), while the run quotes the whole path, so a Windows user folder with a space failed doctor's Python check and stopped the launch. Doctor now runs it as one path; a quoted value fails with the reason.
• A folder in a task's Files (src/) covers the paths under it in task-checks, but lane validation, join waves and the owner map compared exact strings. One rule now holds everywhere: two paths overlap when equal or when one is a folder holding the other. derive-lanes groups such tasks so it does not propose a split validation refuses.
• The start check after a failing verify could take the last free agent, return nothing, have its retry refused and turn a finished run into a budget stop. It is now advisory: one call, no retry, no availability probe, and no refusal latch.
• A task_checks entry for a lane with no test, lint or build command was accepted but never ran; validation now reports it.
• A batch of A and B runs as unit A-B, which a real task A-B could collide with; validation now rejects any colliding batch unit id, including part of a batch and other batches, in any letter case.

Also: install.sh removed the installed skill before copying the new one, so a failed copy left none, and it copied untracked files from the checkout. It now stages the copy outside skills/, checks it, swaps it in (restoring the old one if the swap fails), and from a git checkout copies tracked files only.

Every fix has a test that failed first. Full suite on Windows (Python 3.15) at the release head: 1881 tests, 1865 pass, 16 skipped, 0 fail. Built directly; 1.6.9 was released but not installed, and this release includes it.