fix(agent-hooks): run pyright and dump_openapi with --no-sync in an engine-linked app

[hijohnnylin]

Problem

The pyright-stop.sh and openapi-stop.sh stop hooks call a plain uv run. Before it runs the command, uv run syncs the venv to uv.lock. In an app that make engine-link points at a local interp-engine checkout, that sync removes the link and installs the pinned engine release again.

The hook then checks the app against the pinned engine, not the local checkout. Any API that only the local checkout has shows up as pyright errors that are not real. make engine-status then shows the app as stale, and each later stop gives the same errors again.

Fix

When the app has an .engine-linked marker, both hooks add --no-sync. The Makefile already does this for the -dev targets (uv_run). The follow-up message from the pyright hook also mentions --no-sync, so an agent that runs pyright again does not unlink the engine.

The flag is a plain string, not a bash array. Bash 3.2 treats an empty "${a[@]}" under set -u as an unbound variable.

Risk

• For an app with no .engine-linked marker, the command does not change. Only make engine-link writes that marker, and it is gitignored.
• Only agent hooks change: no app code, CI or build files.

Testing

• bash -n passes on both scripts.
• On bash 3.2.57 with set -u, the new form gives uv run pyright without the marker and uv run --no-sync pyright with it. The old array form fails with unbound variable.
• I ran pyright-stop.sh by hand with a stop-hook input, on an engine-linked app. Afterward make engine-status still showed the app as local. Before the fix, the same run removed the link.