pi-synthetic v0.29.0

fd9d96c: Remove the built-in sub-bar integration from the package. It is now distributed as a standalone one-off pi extension installed with pi install https://gist.github.com/aliou/7cce00c3be0c4c94e2bb305a215f5d93 (frozen, unmaintained). The subBarIntegration config option was removed; a config migration drops it and points remaining users at the gist.

9dc4a94: Hide the low thinking level on GLM-5.3-Flash. It degenerates into a repetition loop that burns the full token budget without producing a final answer (same defect as GLM-5.3’s low). The model now exposes only high and max, matching GLM-5.3.