v1.5.0 — agy seats stay in their worktree; --stop

Published to npm as @armoryworks/md-agent@1.5.0.

Fixed

• agy seats ignored the worktree. agy resolves paths against its project, not the process cwd (started bare it works in ~/.gemini/antigravity-cli/scratch), so an isolated agy seat's files landed outside its workspace. Every agy turn now carries --add-dir <seat dir>. Verified live under worktree isolation: files in the workspace, verify PASS, main tree clean.
• --help / unknown flags printed a stack trace; now usage.

New

• md-agent --stop <run-dir> — end a run that has no console (detached, or from another terminal). Places a STOP file the run polls every 2s; clean teardown (seats told to exit, workspaces audited, endedAt stamped); SIGTERM only if the process lingers. touch runs/<dir>/STOP or a hand-placed HALT.txt do the same. SIGTERM itself now tears down cleanly.
• The orchestrator treats a seat that fails verify twice on the same work as stuck — route to another seat (the reviewer), re-scope, or split — instead of bouncing it a third time while the reviewer idles.
• Skill: Watching a run covers --stop.