Tracing helpers

Debug-only wrappers over trace, trace_num and trace_float. Each stringizes the variable name as the label, so the log shows the source identifier next to its value. All four are gated on DEBUG, so they vanish entirely under -DNDEBUG.

#define TRACEVAR(v)  if (DEBUG) trace_num(#v, sizeof(#v)-1, (int64_t)v);
#define TRACEHEX(v)  if (DEBUG) trace(#v, sizeof(#v)-1, v, sizeof(v), 1);
#define TRACEXFL(v)  if (DEBUG) trace_float(#v, sizeof(#v)-1, (int64_t)v);
#define TRACESTR(v)  if (DEBUG) trace(#v, sizeof(#v)-1, v, sizeof(v), 0);

(Abbreviated above; the real definitions add the exact casts.)

Macro	Logs	Argument should be
TRACEVAR(v)	label + signed integer	an integer variable
TRACEHEX(v)	label + hex dump of the buffer	an array (uses sizeof(v))
TRACEXFL(v)	label + XFL float	an int64_t XFL value
TRACESTR(v)	label + text	an array of text (uses sizeof(v))

int64_t balance = 100;
TRACEVAR(balance);      // logs: balance: 100

uint8_t acc[20];
hook_account(acc, 20);
TRACEHEX(acc);          // logs: acc: <40 hex chars>

Expression/statement note: each expands to a bare if (DEBUG) ...;. Do not follow one with an else on your own if — the trailing if will capture it. sizeof pitfall: TRACEHEX/TRACESTR use sizeof(v) for the data length, so v must be an array, not a pointer. Do not rely on trace output on validators — see the note under trace; these are inert above trace log level.