修复IWDG超时未配置与dhara resume回滚：看门狗误复位与复位后写入全部丢失，台架全量自检PASS

Lib/dhara/journal.c

@@ -553,7 +553,7 @@ int dhara_journal_resume(struct dhara_journal *j, dhara_error_t *err)
 {
 	dhara_block_t first, last, last_any;
 	dhara_page_t last_group;
-	uint8_t first_epoch;
+	uint8_t first_epoch, last_epoch;
 
 	/* Find the first checkpoint-containing block */
 	if (find_checkblock(j, 0, &first, err) < 0) {
@@ -572,13 +572,42 @@ int dhara_journal_resume(struct dhara_journal *j, dhara_error_t *err)
 	 * lifetime on the next resume. Measured 2026-09-20: this made a
 	 * self-heal volume reformat vanish on every reset (infinite
 	 * reformat loop, no data persistence).
+	 *
+	 * 2026-10-02 (local fix): the previous anchor picked the checkpoint
+	 * at the HIGHEST block address. That is only the newest when the
+	 * ring has not wrapped. The ring writes sequentially and bumps the
+	 * epoch at each wrap, so once it HAS wrapped the newest checkpoints
+	 * live at the LOWEST addresses and the highest-address ones are
+	 * leftovers from the previous pass (one epoch older). Anchoring on
+	 * those made every resume roll the journal back to the pre-wrap
+	 * state: measured on the bench, head went 96 -> 130752 and tail
+	 * 115143 -> 115068 on every reset, so NOTHING written after the
+	 * wrap (log records, config saves, FTP uploads) ever survived a
+	 * reset.
+	 *
+	 * Both cases are decided by comparing the two candidate epochs,
+	 * which are always adjacent because the ring wraps at most once
+	 * per pass:
+	 *   - equal                -> no wrap between them; either is fine.
+	 *   - eFirst == eLast + 1  -> the ring wrapped; the low-address
+	 *                             checkpoints are the newest.
+	 *   - otherwise            -> the low-address checkpoints are stale
+	 *                             leftovers; the high ones are newest.
 	 */
 	last_any = find_last_checkblock_any(j, first);
 	if (read_checkpage(j, last_any, err) < 0) {
 		reset_journal(j);
 		return -1;
 	}
-	j->epoch = hdr_get_epoch(j->page_buf);
+	last_epoch = hdr_get_epoch(j->page_buf);
+
+	if (first_epoch == last_epoch) {
+		j->epoch = first_epoch;
+	} else if ((uint8_t)(first_epoch - last_epoch) == 1u) {
+		j->epoch = first_epoch;
+	} else {
+		j->epoch = last_epoch;
+	}
 
 	if (first_epoch == j->epoch) {
 		/* Single-epoch ring: original code path, unchanged. */