pkg: build a local .deb; de-duplicate onto DAEMON's systemd/nativehost/man page

DAEMON landed packaging/nativehost/, packaging/systemd/{velox.service,velox.socket}
(real sd_listen_fds() socket activation) and cli/man/velox.1 on main while this was
in flight, duplicating paths this branch had drafted independently. Per CLAUDE.md
(packaging/nativehost/ is DAEMON's; the rest of packaging/ is PKG/QA's), DAEMON's
copies are kept as the single source and this branch's packaging/native-messaging/,
packaging/man/velox.1 and stale packaging/systemd/velox.service are dropped rather
than maintained twice. The root CMakeLists.txt's install() rules now point at
DAEMON's paths directly, install both systemd units (not just velox.service), and
docs/07-packaging.md / packaging/README.md no longer claim there's no socket
activation — there is, and this package now ships it.

Adds the local-test-only .deb itself: debian/{control,rules,postinst,postrm,
changelog,copyright}, a placeholder icon set, the desktop entry and PKG/QA's own
man pages (veloxd.8, velox-gui.1 — velox.1 stays DAEMON's). libveloxcore stays
static (no consumer needs a .so yet); pairing has no real approval UI in this
build (D1 unbuilt), so postinst and packaging/README.md both say VELOX_PAIR_AUTO=1
is required and print it prominently. No PPA, no GPG — local dpkg -i only.

Verified live: dpkg-buildpackage -us -uc -b, dpkg -i, socket activation (systemctl
--user enable --now velox.socket), `velox ls` against the running daemon, lintian
clean, dpkg -r removes the manifest/units and leaves $XDG_DATA_HOME/velox alone.

.gitignore now excludes dpkg-buildpackage's debhelper build tree and obj-*/ (the
debuild output dir) — debian/control et al. stay tracked, everything debhelper
regenerates does not.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_0176u3fTrxegrGNm2yC7r69W

docs/07-packaging.md

@@ -9,16 +9,28 @@ Owner: lane **PKG/QA**. Target: Ubuntu 26.04 LTS.
 /usr/bin/velox-gui
 /usr/bin/velox                       # CLI
 /usr/libexec/velox/velox-nmhost      # native messaging host
-/usr/lib/x86_64-linux-gnu/libveloxcore.so.1
 /usr/share/applications/velox.desktop
 /usr/share/icons/hicolor/*/apps/velox.png
 /usr/share/man/man1/velox.1.gz
 /usr/lib/systemd/user/velox.service
-/usr/lib/systemd/user/velox.socket   # socket activation
+/usr/lib/systemd/user/velox.socket   # real socket activation, see below
 /usr/lib/mozilla/native-messaging-hosts/com.velox.host.json
 /etc/xdg/autostart/velox-gui.desktop # optional, off by default
 ```
 
+`libveloxcore` is **static**, linked into `veloxd`, `velox` and `velox-gui` directly —
+there is no `libveloxcore.so.*` to install. A shared, versioned `libveloxcore.so.1` was
+the original plan here; the user decided against building one for now (no consumer needs
+it as a shared object yet, and it would need CORE's `core/CMakeLists.txt` to grow a
+`SOVERSION`). Revisit as a CORE-lane request if that changes — this doc was corrected in
+the same commit as the decision rather than left describing something unshipped.
+
+`velox.service` and `velox.socket` are both DAEMON's (`packaging/systemd/README.md`,
+`daemon/src/rpc/systemd_activation.cpp`) — real `sd_listen_fds()` socket activation, not a
+plain `exec`. This package installs both units verbatim and lets `dh_installsystemduser`
+(compat 13) pick them up from the install tree; see `packaging/README.md` for what that
+does and does not do at install time for an already-running session.
+
 `postinst` additionally drops per-user native-messaging manifests for the packaging formats
 that need them, and **detects whether Firefox is a snap** — if so it prints (and the GUI's
 first-run wizard shows) a one-line note that the extension will pair over loopback.