MOSFET to power all glass breaks. uC can cycle it to reset all.

12V power.

use voltage divider. measure resistance/voltage to detect various
conditions, w.r.t EOL resistor and the divider. ... divider needed
to interface with lower-voltage PIC.

TEST: voltages/resistances for the various sensor states.

3 PICs: 13 glass breaks. 12 doors.
+1 door for server room.
+1 output for MOSFET
======
total: 27 pins.
reserve: 2 pins per, for I2C. thus: 30 pins.

Door sensors at TTL?

Garage door sensors: unknown. TBD.

Power: lithium ion, and control circuitry?
Enough power for the GSM module?

Glass breaks: 22mA each, maximum. (not fully-sourced/verified)

Main power loss: move to higher alert status

Door sensors: NO/NC? Pull-ups/downs needed.