fix(epg): Silence snprintf buffer truncation warnings

Extend EPG time string buffers from 21 to 74 bytes to silence
compiler warnings about potential buffer truncation.

The actual output is always 20 chars ("YYYYMMDDHHMMSS +0000") plus
null terminator, but the compiler warns because %02d with int
arguments could theoretically produce larger output.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: cfsmp3

src/lib_ccx/ts_functions.h

@@ -50,8 +50,8 @@ struct EPG_rating
 struct EPG_event
 {
 	uint32_t id;
-	char start_time_string[21]; //"YYYYMMDDHHMMSS +0000" = 20 chars
-	char end_time_string[21];
+	char start_time_string[74]; // "YYYYMMDDHHMMSS +0000" = 20 chars, 74 to silence compiler warning
+	char end_time_string[74];
 	uint8_t running_status;
 	uint8_t free_ca_mode;
 	char ISO_639_language_code[4];

src/lib_ccx/ts_tables_epg.c

@@ -125,7 +125,7 @@ void EPG_ATSC_calc_time(char *output, uint32_t time)
 	timeinfo.tm_hour = 0;
 	timeinfo.tm_isdst = -1;
 	mktime(&timeinfo);
-	snprintf(output, 21, "%02d%02d%02d%02d%02d%02d +0000", timeinfo.tm_year + 1900, timeinfo.tm_mon + 1, timeinfo.tm_mday, timeinfo.tm_hour, timeinfo.tm_min, timeinfo.tm_sec);
+	snprintf(output, 74, "%02d%02d%02d%02d%02d%02d +0000", timeinfo.tm_year + 1900, timeinfo.tm_mon + 1, timeinfo.tm_mday, timeinfo.tm_hour, timeinfo.tm_min, timeinfo.tm_sec);
 }
 
 // Fills event.start_time_string in XMLTV format with passed DVB time