I use fish shell only now. Used to only write bash, but I've started writing some fish scripts. I wouldn't try to plan too much WRT shell scripting up front. Just fix your pain points as you go.
I use Calibre and its web server locally. Works great.
Element/Matrix
Happens with Firefox on Linux too. Very annoying.
Wow, 6 years. What was your injury?
I do the same. Using VPN, proxy, Firefox container, tracker blocking, the whole 9 yards. I haven't seen price change based on location/purchase history. I've been looking for signs of this for a while. Prices do fluctuate quite a bit though. The site might have auto-selected a different "ships from" option for you, depending on how you're logged in.
I followed up with customer support. They said go ahead with the order and they will refund me the amount after. They gave me a $5 credit for my trouble. They said they would escalate this issue to the development team.
I only needed one more item to "unlock extra savings up to 15%", so I added an extra item to see what the savings would be. I didn't think the savings matched what was advertised, so I removed an item to see what the difference was (making sure to screenshot before/after this time). Turns out the price of 3 out of 4 items is the same after an extra 5% discount.
But one is ambiguous.
Street address data isn't available for the US. I find the POI in Google Maps in Firefox and then go to Share and open the coordinates in Organic Maps or OsmAnd.
I use emacs, Denote, and markdown-mode to keep a loose Zettlekasten archive of notes.
I use GnuCash for two companies and personal accounting. Love it.