canClickPlace

Checks whether the player can currently click-place a block at pos from their position.

This mirrors the exact placement check done in scheduleCurrentPlacements (same search options, including face-away handling), so a support path never ends at a position the actual placement would reject. On top of that it requires the chosen click point to be unobstructed from the player's current view — if it is not visible (e.g. the target face is occluded by the block itself), the position is rejected and the support search keeps going past it.