Is there any chance to salvage my resin tank after this mess?

The short answer is that while the dust and hairs are annoying and definitly need cleaning, the plastic of the vat itself is likely fine. Most modern vat materials are chemically resistant enough to handle minor exposure to the post-curing resin, so you probably won't have a major structural integrity issue. The contamination concern is mainly about those particulates and any uncured or partially cured resin residue coating the surface.

For the stuck gunk and resin buildup, don't just scrape it dry. You need to saturate the area. Get some isopropyl alcohol and soak the inside of the vat for a good amount of time. The alcohol will soften the cured resin, making it much more flexible and easier to remove without scratching the plastic. Then you can use a plastic scraper to gently lift the residue. Just be careful not to scratch the interior surface while you're doing it. Regarding the dust and hairs, those are much harder to remove completely. If you want to get as clean as possible, you coud try a light dusting with compressed air, followed by a thorough wash with a mild solvent, then dry it completely. If the residue is widespread and you're worried about microscopic particles interfering with future prints, you might consider a quick rinse with some acetone or similar mild thinner, but only if it is rated for your specific plastic type. If the contamination is just minor specks and hair, you're probably fine to keep the vat. If it feels like a constant buildup of gunk and you're allready planning on maintenace, a replacement might be easier, but try the solvent soak first. That usually handles the big gunk issues and lets you decide if it's salvageable.

Don't sweat it, I've done way worse. Left a vat uncovered overnight once and found a moth floating in it the next morning. Strained the resin through one of those fine paint filters and it printed fine for months after.

Honestly the bigger lesson I learned is just keeping a lid or even a cut-up plastic sheet over the vat whenever I walk away, even for a minute. Dust settles fast in a garage shop.

I panicked the same way after a bag of concrete dust from the next room found its way into my vat. What saved it for me was a silicone spatula, the kind meant for cake batter. Soft edge, zero scratches, and it peeled the cured film off in sheets after a short soak. I followed up with a lint roller on the dry film to grab every last hair, which sounds silly but worked better than wiping ever did. If your film still looks smooth and clear under a flashlight when you tilt it, you are fine. Hazy spots are when I start thinking about swapping the film instead of the whole vat.