Merge upstream/main into the fork

Brings the nine commits that are actually the latest on our lineage:
isolated testnet parameters and genesis, optional 2 MB large pages for
RandomX, and five README changes. This is what "up to date" means here --
not the 1.2.2x tags, which carry higher version numbers but were cut
2026-07-30, three weeks before the line we ship, and which upstream/main
does not contain.

Three conflicts, all resolved toward upstream's structure while keeping
what this fork knows:

main.cpp -- upstream moved genesis construction into BuildGenesisBlock() so
mainnet and the new testnet can share it. Verified byte-for-byte before
taking it: MAINNET_GENESIS_TIMESTAMP, _TIME (1753315200), _NONCE (3141),
_HASH, _MERKLE, the scriptPubKey, nBits and nVersion all equal what this
tree built inline. The mainnet genesis hash is unchanged and the asserts
still guard it. Kept our warning about never editing those inputs, and kept
our note that 1753315200 is 2025-07-24, not 2026 -- upstream's comment on
that constant states the wrong year.

net.h -- DEFAULT_PORT = htons(8433) becomes MAINNET_PORT/TESTNET_PORT in
host order. Nothing is lost: net.cpp's GetDefaultPort() applies htons()
itself and is what every caller uses, so the value reaching a sockaddr is
unchanged and mainnet stays on 8433.

selftest.cpp -- the known-tests string had diverged in both directions.
Took the union: upstream's network-params alongside our payout-ledger,
rather than dropping either.

Gates: 15/15 selftests (our 14 plus upstream's network-params), consensus
constants unchanged against e4f898c except the pre-existing
MAX_BLOCK_SIZE_GEN, mainnet genesis intact, compactblock's 17 checks still
pass, money-log check ok, GNU_STACK RW.

1 files changed, 37 insertions, 13 deletions

diff --git a/README.md b/README.md
index 77a0ad8..4453529 100644
--- a/README.md
+++ b/README.md
@@ -8,9 +8,11 @@ CPU-only cryptocurrency. A revival of Bitcoin 0.1.0 with RandomX proof of work a
 
 ![PoW](https://img.shields.io/badge/PoW-RandomX%20(CPU)-2ea44f?style=for-the-badge)
 ![Privacy](https://img.shields.io/badge/addresses-.btf%20anonymous-2ea44f?style=for-the-badge)
+![Tor](https://img.shields.io/badge/tor-onion%20service-7d4698?style=for-the-badge)
 ![Fair Launch](https://img.shields.io/badge/premine-none-2ea44f?style=for-the-badge)
+[![Discord](https://img.shields.io/badge/discord-join-5865F2?style=for-the-badge)](https://discord.gg/n7B2Eamn3)
 
-**[Download](../../releases/latest)**
+**[Download](https://releases.bitflash.network/)** · **[Discord](https://discord.gg/n7B2Eamn3)**
 
 </div>
 
@@ -46,14 +48,14 @@ For a plain SOCKS5 proxy without Tor-specific defaults, use
 
 ## Quick start
 
-Download the [latest release](../../releases/latest) and run. No install, no
-configuration — it connects automatically and starts syncing.
+Download the [latest release](https://releases.bitflash.network/) and run. No
+install, no configuration — it connects automatically and starts syncing.
 
 **Linux:** make the `.AppImage` executable and run it.
 
-**Windows:** extract the `-windows.zip` and run `Bitflash.exe`.
-If you want managed Tor without a separate Tor install, use the
-`-windows-with-tor.zip` package and start Bitflash with `-managedtor`.
+**Windows:** extract the `-windows-with-tor.zip` and run `Bitflash.exe`. Tor is
+bundled and a managed Tor instance starts automatically, so onion transport
+works with no separate install. Pass `-nomanagedtor` to turn it off.
 
 Every release ships a `SHA256SUMS` covering the assets. Verifying takes a second
 and is worth doing:
@@ -83,7 +85,7 @@ Public mirrors should make the latest checksum files available both under the
 versioned release directory and at the release root:
 
 ```text
-https://releases.bitflash.network/v1.2.19/SHA256SUMS
+https://releases.bitflash.network/v1.2.20/SHA256SUMS
 https://releases.bitflash.network/SHA256SUMS        # alias to latest
 ```
 
@@ -166,6 +168,14 @@ words also cover the address the window shows you. **Both still matter** — the
 phrase and the file back up different things, and the difference is where people
 lose money.
 
+Since 1.2.20 the file is a single self-contained `wallet.sqlite` by default. A
+fresh data directory starts on it; an existing Berkeley DB `wallet.dat` keeps
+working and the desktop app converts it in one click on first run, never
+touching the original, which stays as a fallback. Choose a backend explicitly
+with `-walletbackend=sqlite` or `-walletbackend=bdb`, recorded in a
+`wallet-backend` marker in the data directory. See
+[wallet storage](docs/storage.md).
+
 The derivation is written down in [docs/derivation.md](docs/derivation.md), with
 test vectors and a script that reproduces them from scratch. It is there so the
 twelve words keep working even if this software does not: paths, address format
@@ -179,8 +189,11 @@ bitflash -newphrase                          # create it, show it once, exit
 bitflash -restorephrase="twelve words here"  # rebuild a wallet from it
 ```
 
-`-newphrase` installs a BIP32 seed, derives the wallet's key pool and default
-receiving address from it, and prints the words once. It refuses if a phrase
+`-newphrase` installs a BIP39/BIP32 seed and derives the wallet as a BIP44 tree
+along `m/44'/4346950'/0'/…` — coin type **4346950** is `0x425446`, the ASCII
+bytes `BTF`, registered in [SLIP-0044](https://github.com/satoshilabs/slips/blob/master/slip-0044.md).
+It builds the key pool and default receiving address from the seed, and prints
+the words once. It refuses if a phrase
 already exists: replacing one silently would strand every coin on addresses the
 written-down words no longer describe.
 
@@ -207,6 +220,10 @@ matter.
 
 ### The file
 
+Under the SQLite default the wallet is one self-contained `wallet.sqlite`, and
+`-backupwallet` writes a matching `.sqlite` copy that opens on its own — no
+sidecar directory. The Berkeley DB notes below apply to a legacy `wallet.dat`.
+
 **Copying `wallet.dat` on its own is not a backup.** Berkeley DB ties the file
 to the environment in the `database/` subdirectory beside it, so a lone
 `wallet.dat` will not open elsewhere — the keys are all still in there, and the
@@ -244,7 +261,7 @@ as a verdict to somebody who has just lost a wallet.
 
 ### When wallet.dat itself will not open
 
-Everything above still runs through Berkeley DB. If the database is the thing
+A legacy `wallet.dat` runs on Berkeley DB. If that database is the thing
 that is broken — a build that will not read it, a file truncated by a bad copy,
 an environment beyond recovery — the keys are usually still fine, and you can
 take them out as text:
@@ -348,10 +365,12 @@ Other options worth knowing:
 
 ```bash
 -datadir=PATH    # wallet and chain data elsewhere
--port=N          # P2P listen port, default 8433
+-testnet         # isolated test network genesis, datadir, port 18433, and magic
+-port=N          # P2P listen port, default 8433; testnet default 18433
 -socks=HOST:PORT # SOCKS5 for outbound Nostr, .btf relay, and onion peer dials
 -tor[=HOST:PORT] # Tor mode; default local Tor SOCKS5 proxy is 127.0.0.1:9050
 -managedtor[=PATH] # start Tor, create a hidden service, advertise its onion
+-nomanagedtor    # disable the automatic bundled-Tor startup
 -onionservice=HOST.onion:PORT # advertise this node's Tor hidden service
 -debug           # verbose log; without it debug.log is nearly silent
 -help            # full list
@@ -372,6 +391,10 @@ proxy. IPv6 proxy endpoints use brackets, for example `-socks=[::1]:9050`.
 and signed direct `.onion` peer dials through Tor, and keeps external-IP probes
 disabled. Use `-tor=HOST:PORT` when Tor listens somewhere else.
 
+The desktop app starts a managed Tor automatically when no other Tor option is
+set, so onion transport works out of the box; `-nomanagedtor` turns that off.
+For a headless node, ask for it explicitly:
+
 `-managedtor[=PATH]` starts a Tor process for this node, writes a local `torrc`,
 creates a v3 hidden service for port `8433`, routes outbound discovery through
 that Tor instance, and signs the generated `.onion:8433` endpoint into the
@@ -496,7 +519,8 @@ windows-tor` to require the extra signature check.
 | Addressing | `.btf` rendezvous — see the caveats above |
 | Premine | None |
 | Pool server | Built-in — `.btf` rendezvous only |
-| Wallet recovery | Twelve-word phrase (BIP39 + BIP32), plus file backup |
+| Wallet recovery | Twelve-word phrase (BIP39 + BIP32 + BIP44, coin type 4346950), plus file backup |
+| Wallet storage | SQLite `wallet.sqlite` by default, or Berkeley DB `wallet.dat` |
 
 The halving interval is the number most people get wrong coming from Bitcoin.
 Same 210,000 blocks, but at two minutes instead of ten, so it arrives in about
@@ -504,6 +528,6 @@ ten months rather than four years.
 
 ---
 
-Experimental software. Young network. Don't put in more than you are willing to lose.
+Young network. Keep your node current and don't put in more than you are willing to lose.
 
 MIT. Built on Bitcoin 0.1.0 (Satoshi Nakamoto, 2009).