Don’t think so - it’s more deep purple than pale blue and the flower is very petunia like even though it’s is clearly not a petunia.
Looks like an ornamental flax to me. How big is the flower?
Another vote for flax. I believe they do come in a variety of shades. I grow red flax, so if you get both red and blue flax, then to find a purple tinged one is not so unusual.
Well- it seems that this is actually a “purple oleander”.
I’ve been away for a bit with a lovely lady looking after my two Burmese boys. She assures me that this is a purple oleander ( and she’s pretty knowledgeable plant wise). I’ve looked it up and I’m inclined to agree.
However - VERY toxic for humans and little cats!
The leaves don't look "right" for oleander - they're thicker. I'm not convinced!
Could it be Ruellia then?
That came up when I searched for purple oleander.
Never heard of Ruellia before! Described as a wild petunia - which matches what you said in #3.
Could be?