release: bump to v1.3.0 and document the signing step that was never performed

The tree stamped 1.2.0 in both configure.ac and src/clientversion.h, but
v1.2.0 is an annotated tag already pushed at fad05d3ab and dev is 27
commits past it. Both trees therefore produced CLIENT_VERSION 1020050 and
announced an identical /DragonX:1.2.0/ subversion, so a released binary
would have been indistinguishable from the tag on the wire, in
getnetworkinfo, and to the wallet's in-app updater -- destroying the only
provenance check users have: build the tag, compare the binary.

Bump MINOR rather than REVISION: the delta since v1.2.0 adds a subsystem
(RandomX stratum) and a new RPC (stratummine).

  configure.ac, src/clientversion.h  1.2.0 -> 1.3.0 (CLIENT_VERSION 1030050)
  doc/man/*.1                        version strings restamped
  contrib/debian/changelog           1.3.0 entry for the 27 commits
  src/chain.h                        stale "CLIENT_VERSION is 1010050" comment

Man page *content* still needs a real regeneration: util/gen-manpages.sh
requires help2man and built 1.3.0 binaries, so it belongs in the release
build, where it will also pick up the new stratum options.

doc/release-process.md is why v1.1.0 and v1.2.0 were tagged but never
became releases. Followed verbatim it produced a release the wallet
refuses to install:

  - it directed releases to a branch named `dragonx`, which does not
    exist; releases are cut on `master`
  - it never once mentioned signing, yet the updater pins an ed25519 key
    and sets kDaemonRequireSignature = true, so an unsigned release is
    refused outright and every user silently stays on their old daemon
  - it did not require the release tag to be annotated, and genbuild.sh
    calls `git describe` without --tags, so a lightweight tag stamps the
    build `v<older-tag>-<sha>` instead of the release version -- which is
    exactly what happened to v1.0.0 through v1.0.3
  - it referenced util/build-debian-package-ARM.sh, which is not in tree

Adds the signing and checksum-table steps, the annotated-tag requirement
with a `git describe` verification, and the rule that a new version must
exceed every existing tag including unpublished ones.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FU87LdsJZiZkfq1eXubpeo

contrib/debian/changelog

@@ -1,3 +1,31 @@
+dragonx (1.3.0) stable; urgency=medium
+
+  * RandomX stratum mining support: the daemon can serve stratum clients
+    directly, with a reference miner behind the stratummine RPC for testing.
+  * Stratum fixes found by audit: a malformed 63-character job_id no longer
+    aborts the daemon; each block is paid to the miner that actually found it
+    rather than to whichever client asked for work first; and a low-difficulty
+    share is now rejected before it costs a RandomX hash.
+  * Fix -connect never dialing its targets, so a node pinned to specific peers
+    reaches them instead of silently falling through to peer discovery.
+  * Remove roughly 7,100 lines of dead code, including the CBOPRET price
+    validation in the coinbase check, whose guard could not be true on any
+    chain, and adaptive-PoW difficulty logic that DragonX does not enable.
+  * Honor a command-line -rpcpassword across restarts, and fix a misspelled
+    -rpcusername key that silently discarded the configured RPC user.
+  * Default -checkpoints off on regtest so an isolated node leaves initial
+    block download, instead of staying in IBD forever and disabling every
+    operation gated on it.
+  * Release cs_main and the mempool lock on the miner's isStake error paths;
+    the leak presented as a permanent stall rather than a slow response.
+  * Windows cross-build: the mingw target links and finds librustzcash, and a
+    fs::path::c_str() regression in init no longer breaks the build.
+  * Stamp container builds with the real version instead of "-unk".
+  * Repair the qa/rpc-tests harness far enough to start a DragonX node and
+    build the shared test chain; it previously started mainnet nodes.
+
+ -- DragonX Developers <dev@dragonx.is>  Mon, 31 Aug 2026 03:46:19 +0000
+
 dragonx (1.2.0) stable; urgency=medium
 
   * Auto-shield matured coinbase into a wallet-owned Sapling address on a block