chore(lite): send-smoke harness + checkpoint generator

tools/lite_send_smoke drives the real SDXL backend's exact GUI send path
(newaddr/status/list/tree/send/rescan) for diagnosing shielded sends.
scripts/gen-lite-checkpoints.sh generates verified mainnet checkpoints from a
synced dragonxd (getblockhash + getblockmerkletree), self-checking against a
known checkpoint before emitting.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

scripts/gen-lite-checkpoints.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+# Generate SDXL lite-wallet mainnet checkpoint entries from a fully-synced dragonxd.
+# Each entry is (height,"blockhash","serialized_sapling_tree") in checkpoints.rs format.
+# Fills the 1,770,000 -> tip gap so wallets reseed close to their birthday on rescan,
+# bounding the (divergence-prone) compact-block replay span. Usage:
+#   scripts/gen-lite-checkpoints.sh [start] [step] > /tmp/new_checkpoints.txt
+set -euo pipefail
+
+CLI=${DRAGONX_CLI:-/home/d/dragonx/src/dragonx-cli}
+START=${1:-1770000}
+STEP=${2:-10000}
+
+tip=$("$CLI" getblockcount)
+end=$(( (tip / STEP) * STEP ))
+
+# Sanity: confirm the method reproduces a KNOWN checkpoint tree before trusting it.
+ref_hash=$("$CLI" getblockhash 1760000 | tr -d '"[:space:]')
+ref_tree=$("$CLI" getblockmerkletree 1760000 | tr -d '"[:space:]')
+expect_hash="0000545a45b8d4ee4e4b423cb1ea74d67e3a04c320c6ea2f59ee06c08f91a117"
+if [ "$ref_hash" != "$expect_hash" ]; then
+  echo "ABORT: getblockhash 1760000 = $ref_hash != known $expect_hash" >&2; exit 1
+fi
+echo "# self-check: 1760000 hash matches; tree len=${#ref_tree}" >&2
+
+n=0
+h=$START
+while [ "$h" -le "$end" ]; do
+  hash=$("$CLI" getblockhash "$h" | tr -d '"[:space:]')
+  tree=$("$CLI" getblockmerkletree "$h" | tr -d '"[:space:]')
+  if [ -z "$hash" ] || [ -z "$tree" ]; then echo "ABORT: empty hash/tree at $h" >&2; exit 1; fi
+  printf '\t(%s,"%s",\n\t\t"%s"\n\t),\n' "$h" "$hash" "$tree"
+  n=$((n+1))
+  h=$((h+STEP))
+done
+echo "# generated $n checkpoints from $START to $end (tip=$tip)" >&2