For those uses, there's a fairly decent approach ["missile"] or hover ["bomber"] stage that is probably plenty vulnerable to autonomous PDS via 12 guage medicine.
Tracking / detection could even be passive, partly acoustic, partly EO/IR, with only a small fire control radar if you really want it.
I don't think western common folks grok how depraved that country is in terms of doing good work, reward systems for such and corruption on every single level. puttin' built a mafia state and pushed this behavior from top->bottom, and these are side effects. Not some soviet competence and discipline, which wasn't stellar either but light years ahead of current state.
1) Russia suspended the treaty 2023, so it is not relevant here.
2) The use of hangars is not prohibited, as can be seen by the climatized hangars that the US keeps their B1 in.
3) Russia has announced plans for such reinforced hangars years ago, but very likely some dacha or yacht had higher priority.
When I said "triggered" I meant you would enable it when under attack, at which point it doesn't matter if they know you're there anymore.
The problem with any point defense system is radiating any energy makes you a big target. So you would want a passive (EO/IR?) or triggered active/passive system.