🥌🤹🏼‍♀️ ↝ [SSG-187]: User actions + responses

[Gizmotronn]

Alerts & milestones now have a clear value, shown to the user, and a clear usecase with regards to the new tech tree

#184 #183

[height]

Link Height tasks by mentioning a task ID in the pull request title or commit messages, or description and comments with the keyword link (e.g. "Link T-123").

💡Tip: You can also use "Close T-X" to automatically close a task when the pull request is merged.

[Gizmotronn]

Massive amount of code.
Structures in p.gen landmarks coming, plus more customisers next week (and then integration into main gen)
Eventually, we'll move the api routes into a standalone library, too.