While not definite I'm leaning towards
Steatoda nobilis
I wouldn't worry to much - just don't go sticking your fingers in its web

(they can bite, but aren't an aggressive spider - they have poor eyesight and would much rather run away as you've seen - push comes to shove they'll bite you.)
Regardless of what the papers say - they aren't deadly (common name for this family is the 'False widows')
It's when people have allergic reaction to bites (same as wasp and bee stings) that problems occur.
More info on their bites
Generally classed as Steatodism
The clinical presentation of Steatoda bites was characterised by moderate to severe regional pain (26%), with a mean duration of six hours, and systemic effects in 30%, notably nausea, headache, malaise, and lethargy.
THE GLOBAL EPIDEMIOLOGY, SYNDROMIC CLASSIFICATION, MANAGEMENT, AND PREVENTION OF SPIDER BITES by JAMES H. DIAZ
However - bites are very rare and are always in self defence (as you can see from the results only a quarter - ish were moderate or severe - it depends how much venom was used)