Merge upstream v1.2.19 into the fork

Merges upstream tag v1.2.19 (9e39a50) into merge/upstream-1.2.18 (991853f).
Unlike the 1.2.15->1.2.18 replay, bc3de30 is a true ancestor of our branch via
a9b4f89, so this is an ordinary three-way merge with merge-base bc3de30.

Delta: 36 files, +3265/-163, the Tor onion transport (managed Tor, signed
direct onion endpoints, onion-only dial mode) and the nHDNext restore fix.
src/main.cpp, main.h, script.cpp/h and db.cpp/h are byte-identical between the
two tags, and the poll() socket loop carries no diff hunks, so the merge is
consensus-neutral and the soak-tested socket paths are unchanged. relay/ is
untouched; the payout ledger (rpc.cpp) is untouched.

7 conflict blocks in 6 files, resolved as follows.

Makefile -- VERSION. Ours: stays 1.2.19+sec with the naming comment updated,
so artifacts from this tree cannot be mistaken for the upstream release.

src/Makefile, src/makefile.mingw -- HEADERS list. Ours (no market.h) plus
their tor.h. NODE_OBJS auto-merged correctly: no market.o, tor.o present.

src/selftest.cpp -- known-tests list. Union: payout-ledger (ours) and
managed-tor (theirs).

src/main_gui.cpp -- one block. Our /dumpaddresses kept; their
BtfStopManagedTor() on the StartNode failure path taken. The /rvrelay pin,
/noannounce and the marketplace removal auto-merged and were verified intact.

src/nostr.cpp -- two blocks in ResolveDescriptor. Signature takes both
out-params (our fExchangeOk, their rawOut). The body keeps our
drain-to-EOSE read -- returning early poisons the pooled socket for the next
caller -- and adds their rawOut capture. Our TLS 1.2 floor
(SSL_CTX_set_min_proto_version) is untouched by this merge; upstream 1.2.19
still has no floor of its own.

Upstream's release commit also added four build logs and a compiled Python
cache (build-1219.log, build-17.log, build-appimage.log, build-node.log,
scripts/__pycache__/bitflash_chain.cpython-313.pyc). Removed here; they are
build output, not source.

1 files changed, 22 insertions, 0 deletions

diff --git a/src/test_btfaddr.cpp b/src/test_btfaddr.cpp
index b40dcc1..8de426e 100644
--- a/src/test_btfaddr.cpp
+++ b/src/test_btfaddr.cpp
@@ -86,6 +86,7 @@ int main()
     }
 
     const std::string ENC_HEX = "aabbccddeeff00112233445566778899aabbccddeeff00112233445566778899";
+    const std::string ONION = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcd.onion:8433";
 
     // helper: fresh keypair -> (seckey, xonly pubkey)
     auto newKey = [&](unsigned char sk[32], unsigned char pk[32]) {
@@ -108,6 +109,17 @@ int main()
         CHECK(!btf::VerifyDescriptor(ctx, d, pk2, bad), "different key rejected");
     }
 
+    printf("descriptor_signs_optional_onion_endpoint\n");
+    {
+        unsigned char sk[32], pk[32]; newKey(sk, pk);
+        std::string d = btf::SignDescriptor(ctx, sk, ENC_HEX, "meeting-node-abc", 1000, ONION);
+        CHECK(!d.empty(), "sign produced onion descriptor");
+        btf::Descriptor got;
+        CHECK(btf::VerifyDescriptor(ctx, d, pk, got), "onion descriptor verifies");
+        CHECK(got.meeting_node == "meeting-node-abc" && got.enc == ENC_HEX &&
+              got.created == 1000 && got.onion == ONION, "onion fields match");
+    }
+
     printf("descriptor_rejects_tampering\n");
     {
         unsigned char sk[32], pk[32]; newKey(sk, pk);
@@ -117,6 +129,16 @@ int main()
         CHECK(!btf::VerifyDescriptor(ctx, j.dump(), pk, o), "tampered meeting_node rejected");
         json j2 = json::parse(d); j2["enc"] = "00000000000000000000000000000000000000000000000000000000deadbeef";
         CHECK(!btf::VerifyDescriptor(ctx, j2.dump(), pk, o), "tampered enc rejected");
+
+        std::string d3 = btf::SignDescriptor(ctx, sk, ENC_HEX, "node-1", 5, ONION);
+        json j3 = json::parse(d3);
+        j3["onion"] = "bcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcde.onion:8433";
+        CHECK(btf::VerifyDescriptor(ctx, j3.dump(), pk, o) && o.onion.empty(),
+              "tampered onion ignored rather than trusted");
+        json j4 = json::parse(d3);
+        j4["sig3"] = std::string(128, '0');
+        CHECK(btf::VerifyDescriptor(ctx, j4.dump(), pk, o) && o.onion.empty(),
+              "bad onion signature ignored rather than trusted");
     }
 
     printf("full_resolve_chain_from_address\n");