Declare power measurement in the FTMS feature bitmask

The Fitness Machine Feature characteristic (0x2ACC) reported 0x1483 for a
cycle machine: average speed, cadence, resistance level, heart rate and
elapsed time. Bit 14, power measurement, was clear.

That contradicted what the machine actually sends. Indoor Bike Data (0x2AD2)
sets flags bit 6 and carries the instantaneous power field in every
notification, and QZ had real power to report - up to 35 W in the session
that exposed this.

Rouvy subscribes to 0x2AD2 and 0x2A63 without consulting the feature
bitmask, so it never noticed. MyWhoosh reads 0x2ACC first and believes it:
seeing no power capability it subscribed only to CSC 0x2A5B, took cadence
and speed from crank revolutions, and left its power tile at 0 W with
nothing feeding it. Discovery, connection and the control point handshake
all succeeded, which made this look like a data path failure rather than a
capability declaration.

Set bit 14 so the bitmask matches the notifications: 0x1483 -> 0x5483.
Target setting features are unchanged. The treadmill entry is untouched.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: nickolas122

src/devices/dircon/dirconmanager.cpp

@@ -48,7 +48,9 @@ using namespace std::chrono_literals;
 #define DM_BT(A) QByteArrayLiteral(A)
 
 #define DM_CHAR_OP(OP, P1, P2, P3, ZWIFT_ENABLED)                                                                     \
-    OP(FITNESS_MACHINE_CYCLE, 0x2ACC, DPKT_CHAR_PROP_FLAG_READ, DM_BT("\x83\x14\x00\x00\x0C\xE0\x00\x00"),             \
+    /* 0x5483 adds bit 14, power measurement. 0x2AD2 always carried power (flags bit 6); \
+       clients that trust this field - MyWhoosh does, Rouvy does not - saw 0 W. */       \
+    OP(FITNESS_MACHINE_CYCLE, 0x2ACC, DPKT_CHAR_PROP_FLAG_READ, DM_BT("\x83\x54\x00\x00\x0C\xE0\x00\x00"),             \
        DP_PROCESS_WRITE_NULL, P1, P2, P3)                                                                              \
     OP(FITNESS_MACHINE_CYCLE, 0x2AD6, DPKT_CHAR_PROP_FLAG_READ, DM_BT("\x0A\x00\x96\x00\x0A\x00"),                     \
        DP_PROCESS_WRITE_NULL, P1, P2, P3)                                                                              \