Bump to 1.2.12 (#97)

Version bump for the 1.2.12 release. One line of Makefile; the release notes live here.

## The reason this release is not optional

**#87 — a node that was mining before 1.2.11 can come back as a relay and never say so.** The 1.2.11 mining rework left `fGenerateBitcoins` readable on its own: a wallet carrying that flag from an older build, with no mining mode stored beside it, loads as "not mining" and the window shows nothing wrong. It happened here, on a real node, and it was found only because somebody looked at the hashrate. Anyone running 1.2.11 who mined on an earlier build should assume they are affected.

## Recovery phrase (#93, #96)

Twelve words that bring a wallet back. Proved end to end before merging: a live wallet was paid on a derived address, `wallet.dat` was deleted, and the coin came back from the phrase alone.

- `-newphrase` creates a phrase, installs the seed, fills the key pool from it and shows the words once. It refuses when a seed already exists.
- `-restorephrase="WORDS"` installs the seed and walks forward in batches of 100, rescanning after each and stopping when a batch turns up nothing. `-restoredepth=N` to look further.
- `-newaddress` prints the next receiving address; `-showderived=N` lists what a phrase produces.
- The same two operations are reachable from the window.

**What the phrase does not cover, stated plainly:** keys that existed before the seed was installed — including the wallet's original default address — are not derived from it and do not come back from the words. The commands say this at the point of use. Keep the `wallet.dat` backup as well; the phrase is a second line, not a replacement.

The words are printed to the terminal only, never to `debug.log`.

## Wallet safety

- **#88** — `ScanForWalletTransactions` plus `-rescan`: the node can now walk the chain for coins a key owns but the wallet never saw. `-importwallet` scans too. Without this, restoring from a phrase would have derived the right keys and found nothing.
- **#89, #90** — a backup panel in the window, with the default backup written outside the directory it protects.
- **#95** — a scan with no chain data loaded is refused instead of reporting "no transactions found", which read as a verdict to somebody who had just lost a wallet.

## Tests and diagnostics

**#91** wallet key pool self-test, **#92** self-test output where the person running it can see it, **#94** MSYS2 argument conversion (use `-selftest=...`, not `/selftest=...`, under MSYS2). `make tests` runs the BIP32/BIP39 vectors and both wallet self-tests on Linux and Windows.

## Still not fixed

The socket accounting shipped in 1.2.11 is instrumentation, not a fix — sockets still leak. The three obvious causes have been measured and eliminated; the next step is reading a real node's diagnostic report, not another guess.

0 files changed, 0 insertions, 0 deletions