Turn auto trim into a fly-by-wire flight computer

Pitch input becomes a rate command; the computer measures the pitching torque
without its own surfaces (airframe stability, thrust line, weight offset) and
cancels it with dynamic inversion, so relaxed-stability craft stay controllable.
Replaces trimAuthority with flightComputer* config values.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YVREx3uo7nz1FEhzveWTUh

src/main/resources/assets/improved_aerodynamics/lang/en_us.json

@@ -1,8 +1,8 @@
 {
   "key.categories.improved_aerodynamics": "Improved Aerodynamics",
   "key.improved_aerodynamics.toggle_auto_trim": "Toggle auto trim",
-  "message.improved_aerodynamics.auto_trim.on": "Auto trim on",
-  "message.improved_aerodynamics.auto_trim.off": "Auto trim off",
+  "message.improved_aerodynamics.auto_trim.on": "Flight computer on (auto trim)",
+  "message.improved_aerodynamics.auto_trim.off": "Flight computer off (auto trim)",
   "message.improved_aerodynamics.auto_trim.unavailable": "Auto trim on, but it needs physicsRateAerodynamics enabled in the server config",
   "message.improved_aerodynamics.auto_trim.no_seat": "Sit in a Warium control seat to use auto trim",
   "message.improved_aerodynamics.auto_trim.no_node": "This seat is not linked to a vehicle control node",