feat: S12 — vcucmd 3-state command from VCU (replaces binary vcustop)

Promote 0x212 byte 3 from S11's binary vcustop to the full Dilong-style
OBC_ControlCMD vocabulary:
  0 = Charging — walk to / hold at EVSEACTIVATE, produce current
  1 = Stopped  — sit idle in OFF/WAITSTART/ENABLE, no current
  2 = Complete — drop to STOP (cycle terminated by VCU)

VCU is now authoritative for the charge-cycle lifecycle. The charger
keeps hardware-level wisdom (EVSE pilot via CheckStartCondition,
plug-out safety via CheckUnplugged, module-fault detection via
CheckChargerFaults) but obeys vcucmd for "should I be charging?".

FSM changes:
  - ENABLE→ACTIVATE now gated on vcucmd==Charging (was unconditional).
    ENABLE on vcucmd==Complete drops to STOP; vcucmd==Stopped holds
    HV-armed waiting for next Charging command.
  - EVSEACTIVATE self-decided exits (CheckVoltage, CheckTimeout) are
    gone. Those were band-aids for the absence of an authoritative VCU
    stop signal. vcucmd==Stopped now parks back in ENABLE (HV held);
    vcucmd==Complete drops to STOP. CheckUnplugged + CheckChargerFaults
    still own hardware-safety exits.
  - STOP→OFF now also triggers on vcucmd != Complete (was unplug-only).
    This is the fix for the "raise ChargeLimit mid-COMPLETE doesn't
    restart charging" wedge — the VCU's vcucmd flip from Complete to
    Stopped on a limit-raise lets the natural OFF→WAITSTART→ENABLE→
    ACTIVATE→EVSEACTIVATE flow resume charging without an unplug cycle.

Param rename vcustop→vcucmd. External tooling that reads/writes the
S11 vcustop param via the openinverter web UI will see the new vcucmd
param with 3-state semantics — single-user bench, acceptable.

VERSTR bumped to S12.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

include/param_prj.h

@@ -109,7 +109,7 @@
     VALUE_ENTRY(c3udc,       "V",     2035 ) \
     VALUE_ENTRY(c3idc,       "A",     2036 ) \
     VALUE_ENTRY(tmpobcmax,   "°C",    2051 ) \
-    VALUE_ENTRY(vcustop,     OFFON,   2052 ) \
+    VALUE_ENTRY(vcucmd,      VCUCMDS, 2052 ) \
     VALUE_ENTRY(test_time,   "s",     3000 ) \
     VALUE_ENTRY(test_timer_flag,   "X",     3001 ) \
     VALUE_ENTRY(test_timer_icvalue,   "X",     3002 ) \
@@ -119,6 +119,12 @@
 #define OPMODES      "0=Off, 1=Run"
 #define CHARGERS     "1=Charger1, 2=Charger2, 4=Charger3"
 #define OFFON        "0=Off, 1=On"
+// SKUDAK-S12: VCU→charger control command on 0x212 byte 3. Mirrors the Dilong
+// path's OBC_ControlCMD vocabulary exactly so VCU code paths can be reused.
+//   0 = Charging — VCU wants current to flow; walk to / hold at EVSEACTIVATE
+//   1 = Stopped  — VCU is not driving a cycle; sit in OFF/WAITSTART/ENABLE
+//   2 = Complete — VCU has terminated the cycle; drop to STOP
+#define VCUCMDS      "0=Charging, 1=Stopped, 2=Complete"
 #define CHFLAGS      "0=None, 1=Enabled, 2=Fault, 4=CheckAlive"
 #define STATES       "0=Off, 1=WaitStart, 2=Enable, 3=Activate, 4=Run, 5=Stop"
 #define INPUTS       "0=Type2, 1=Type2-3P, 2=Type1, 3=Manual, 4=Manual-3P, 5=Type2-Auto"
@@ -151,7 +157,18 @@
 // it sets vcustop=1; ChargerStateMachine's EVSEACTIVATE case transitions to
 // STOP immediately, the J1772 CP signal drops, EVSE stops delivering AC,
 // VCU_IsCharging() returns 0, water pumps power down naturally.
-#define VERSTR STRINGIFY(4=VER-S11)
+// -S12 promotes byte 3 from a binary vcustop flag to the full 3-state
+// VCUCMDS vocabulary (0=Charging, 1=Stopped, 2=Complete), matching the
+// Dilong OBC_ControlCMD exactly. The internal FSM now obeys vcucmd for
+// lifecycle transitions: ENABLE only advances to ACTIVATE on Charging, STOP
+// returns to OFF when vcucmd flips back to Charging/Stopped (fixes the
+// "raise ChargeLimit mid-COMPLETE doesn't resume" wedge — teslacharger was
+// stuck in STOP because STOP only exited on CheckUnplugged). The self-
+// decided EVSEACTIVATE exits (CheckVoltage, CheckTimeout) are stripped; the
+// VCU is now authoritative for when charging starts and stops. The charger
+// retains hardware-level wisdom: CheckUnplugged() still forces OFF from any
+// state, and CheckStartCondition() still gates OFF→WAITSTART on EVSE pilot.
+#define VERSTR STRINGIFY(4=VER-S12)
 
 /***** enums ******/
 
@@ -175,6 +192,18 @@ enum states
    STOP
 };
 
+// SKUDAK-S12: VCU→charger command vocabulary on 0x212 byte 3. Must match
+// the values exposed via VCUCMDS enum string AND the VCU's
+// VCU_OIOBCCommand_t enum (stm32-hal-vcu Core/Inc/applications/charger/
+// charger_types.h). Updating one without the others silently breaks the
+// charge state machine, so keep them in lock-step.
+enum vcucmds
+{
+   VCUCMD_CHARGING = 0,
+   VCUCMD_STOPPED  = 1,
+   VCUCMD_COMPLETE = 2
+};
+
 enum _canspeeds
 {
    CAN_PERIOD_100MS = 0,