refactor(packaging): split into dispatch/dispatch-systemd/dispatch-s6, separate dispatch-electron, add bun-based frontend serve

PKGBUILD is now a split package producing three .pkg.tar.zst files in one
makepkg run:
  - dispatch          base application files (/opt/dispatch), CLI wrappers
                       (dispatch-api, dispatch-frontend), env configs
                       (/etc/dispatch/dispatch-api.conf,
                        /etc/dispatch/dispatch-frontend.conf)
  - dispatch-systemd  systemd user units for dispatch-api + dispatch-frontend
                       (conflicts with dispatch-s6)
  - dispatch-s6       s6-rc service pipelines (-srv + -log) for both services
                       (conflicts with dispatch-systemd)

The Electron desktop wrapper moved to its own self-contained PKGBUILD at
packaging/electron/, producing dispatch-electron. It bundles its own copy of
the frontend dist + electron entry points under /opt/dispatch-electron and
does not depend on the base dispatch package, so users can install it
standalone and point VITE_API_URL at any backend at build time.

Files under packaging/ are now read directly from ${_projectdir}/packaging/
rather than via source=(); the two s6 service dirs share basenames (run,
type) which would collide inside ${srcdir}.

New frontend static server: packages/frontend/serve.ts uses Bun's built-in
HTTP server (no extra runtime deps) with SPA fallback to index.html and
path-traversal protection. PORT/HOST/DIST_DIR overridable via env. Exposed
as 'bun run --cwd packages/frontend serve' and via /usr/bin/dispatch-frontend.

Build scripts:
  - bin/build-pkg            now prints the freshest built packages
  - bin/install-pkg          installs dispatch + dispatch-systemd by default;
                              accepts package names or --all; searches both
                              packaging/ and packaging/electron/
  - bin/build-pkg-electron   new, builds the electron split
  - bin/build-pkg-windows    replaces bin/windows-pkg; drops the hard-coded
                              WSL copy step, just prints the win-unpacked path

.gitignore extended to cover packaging/*.tar.zst and packaging/electron/{src,pkg,*.pkg.tar.zst,*.tar.zst}.

3 files changed, 31 insertions, 0 deletions

diff --git a/packaging/s6/dispatch-api-srv/producer-for b/packaging/s6/dispatch-api-srv/producer-for
new file mode 100644
index 0000000..88f7df2
--- /dev/null
+++ b/packaging/s6/dispatch-api-srv/producer-for
@@ -0,0 +1 @@
+dispatch-api-log
diff --git a/packaging/s6/dispatch-api-srv/run b/packaging/s6/dispatch-api-srv/run
new file mode 100644
index 0000000..5754e3d
--- /dev/null
+++ b/packaging/s6/dispatch-api-srv/run
@@ -0,0 +1,29 @@
+#!/bin/sh
+# dispatch-api service — runs the Dispatch backend API as the `tradam` user.
+# stdout/stderr are piped to dispatch-api-log via the s6-rc pipeline.
+
+DISPATCH_CONF="/etc/dispatch/dispatch-api.conf"
+DISPATCH_DIR="/opt/dispatch"
+
+if [ -f "$DISPATCH_CONF" ]; then
+    set -a
+    . "$DISPATCH_CONF"
+    set +a
+fi
+
+cd "$DISPATCH_DIR" || exit 1
+
+# Merge stderr into stdout so both get logged by the consumer.
+exec 2>&1
+
+# Drop privileges to tradam and run bun.
+exec /usr/bin/s6-setuidgid tradam \
+    /usr/bin/env \
+        HOME=/home/tradam \
+        USER=tradam \
+        LOGNAME=tradam \
+        PATH=/usr/local/bin:/usr/bin:/bin \
+        NODE_ENV="${NODE_ENV:-production}" \
+        PORT="${PORT:-18390}" \
+        OPENCODE_API_KEY="${OPENCODE_API_KEY:-}" \
+    /usr/bin/bun packages/api/src/index.ts
diff --git a/packaging/s6/dispatch-api-srv/type b/packaging/s6/dispatch-api-srv/type
new file mode 100644
index 0000000..5883cff
--- /dev/null
+++ b/packaging/s6/dispatch-api-srv/type
@@ -0,0 +1 @@
+longrun