Short version: I failed the project, which means I'll fail the MSc as a whole. It's disappointing, but it doesn't really come as much of a shock.
Long version: the results today are provisional, so they could change by the time that the official results are posted (27th October). But I think that's unlikely. I don't know my exact mark, just that it's somewhere between 0% and 49%. One significant thing is that I was marked as "F" rather than "Absent", so that means that they didn't just dismiss my report for being handed in late.
Looking at the handbook (that links to the rules for the coming academic year, but the relevant section is the same), the bottom two paragraphs give a couple of options: either I could be given a month to make a few changes, or I could be allowed to retake the project (i.e. do a different project) over the coming year. But I don't know whether either of these are feasible - they're entirely at the examiners' discretion. Since I don't have any medical reason (e.g. depression) for failing, those options may not apply to me.
I've been getting various emails from the department about lecture courses and so on for the coming academic year. But I think that's just because they haven't updated their email lists yet, to remove all of last year's students. I was a bit more surprised to be issued with a candidate number for the exams, since that number is specific to me (it's not just my copy of a bulk email). However, that could be their automated system saying "generate a unique number for everyone on the list". Since I passed all my exams, it seems odd that they'd expect me to do retakes... The notice (with the results) told us that we're not allowed to contact our supervisors to ask about our provisional results, and this probably falls into the same category, so I'll just file those messages away for the time being.
It's rather frustrating to think that I could have stayed in bed all year, and achieved more than I have. The point is that by failing the MSc, I'm probably worse off (academically speaking) than I would have been if I hadn't taken it at all, i.e. it's bye-bye to any hopes of doing a PhD. And it's not going to look great on my CV either - even if I don't mention the course explicitly, there's still going to be a suspicious looking gap in my work experience, which will attract attention.
In the short term, I'll wait and see what happens when the final results are posted. I've now started back at my old job, so my time is a bit more limited than it used to be, but I'll also try to get the various book errata sorted out, since compiling those lists is probably the most useful thing I achieved (even if it did take time away from my project). There are various lists that I've sent to book authors, which haven't yet appeared on any official site, so I'll host them on my own website for the time being. There's also one other textbook that I'm about half-way through, so I'll decide whether to finish reading it (to get a complete list), or just say "these are the errors from chapters 1-3".
In the long term, I don't know. I could embrace the whole commercial lifestyle thing, by tolerating the job in order to enjoy the salary. For instance, I could start going on foreign holidays, and maybe look at buying my own flat. But that can wait for now.