Add activity indicator, fix window redraw on switch

- Status bar shows (Act: 2,3) for windows with unread messages
- Activity clears when switching to that window
- Re-set scroll region on every window redraw to prevent display issues

main.c

@@ -31,6 +31,7 @@
 
 static int current_level = WL_STATUS;
 static int scroll_offset = 0;  /* 0 = bottom (live), >0 = scrolled up */
+static int win_activity[WL_MAX]; /* activity flag per window */
 static volatile sig_atomic_t got_sigint = 0;
 static volatile sig_atomic_t got_sigwinch = 0;
 
@@ -114,6 +115,24 @@ static void draw_statusbar(void)
 	         prefix_str, nick,
 	         cmodes[0] ? "[" : "", cmodes, cmodes[0] ? "]" : "");
 
+	/* Append activity indicator */
+	char act[64] = "";
+	int apos = 0;
+	for (int i = 0; i < WL_MAX; i++) {
+		if (win_activity[i] && i != current_level) {
+			if (apos == 0)
+				apos += snprintf(act + apos, sizeof(act) - apos, " (Act: ");
+			else
+				apos += snprintf(act + apos, sizeof(act) - apos, ",");
+			apos += snprintf(act + apos, sizeof(act) - apos, "%d", i + 1);
+		}
+	}
+	if (apos > 0)
+		snprintf(act + apos, sizeof(act) - apos, ")");
+
+	size_t blen = strlen(bar);
+	snprintf(bar + blen, sizeof(bar) - blen, "%s", act);
+
 	/* Status bar on second-to-last row */
 	printf("\033[%d;1H\033[7m%-*.*s\033[0m",
 	       term_rows - 1, term_cols, term_cols, bar);
@@ -136,6 +155,7 @@ static void buf_store(int level, const char *line)
 static void redraw_window(void)
 {
 	get_term_size();
+	printf("\033[1;%dr", term_rows - 2); /* ensure scroll region is set */
 	int visible = term_rows - 2;
 	int count = win_buf[current_level].count;
 
@@ -205,7 +225,10 @@ static void wprintf(int level, const char *fmt, ...)
 			printf("\033[%d;1H\n\033[K%s", term_rows - 2, timestamped);
 			draw_statusbar();
 		}
-		/* If scrolled up, don't disturb the view */
+	} else {
+		/* Mark activity on other window */
+		win_activity[level] = 1;
+		draw_statusbar();
 	}
 }
 
@@ -995,6 +1018,7 @@ int main(int argc, char *argv[])
 					int lvl = ch - '1';
 					if (lvl < WL_MAX) {
 						current_level = lvl;
+						win_activity[lvl] = 0;
 						scroll_offset = 0;
 						redraw_window();
 						redraw_input(input_line, input_len, input_pos);