scripts: rebuild the dev loop around build.sh/run.sh

`make` did not parse at all (missing separator at line 139), so every
make target was dead.  The folder also carried three overlapping
launchers (boot.sh, qemu.sh, boot-image.sh) plus a fourth partial one
in the Makefile, `cargo build --package rsdos` copy-pasted eight times,
the QEMU invocation copy-pasted per script, and the test helpers
(fail/wait_log/wait_qemu_exit/qemu_hmp) duplicated in five tests.

New layout:
- scripts/lib.sh: single config (image, OVMF, mem/smp), the one cargo
  invocation (build_all), the one QEMU shape (qemu_args), and the test
  harness (test_boot, wait_log, wait_qemu_exit, qemu_hmp, sendkeys)
- scripts/build.sh: kernel + every bins/* in one pass
- scripts/mksystem.sh: freshness-aware image build that now stages
  every bins/*.efi into /bin/cli|gui (they were never copied before)
- scripts/run.sh: build + stage + boot in one command; --headless,
  --debug (GDB stub), --monitor (HMP socket), --fresh, --mem/--smp/
  --bios/--image; on Wayland it auto-selects XWayland plus
  grab-on-hover so the mouse can be captured (Ctrl+Alt+G toggles)
- scripts/tests/: the five automated tests on the shared harness
- deleted: boot.sh, qemu.sh, boot-image.sh, lib-boot-args.sh,
  build-image-release.sh, build-bootloader.sh (rsboot chain dropped)

The Makefile is now a thin wrapper: make run, make test, make system,
make inspect, make help.  Two-command flow: ./scripts/build.sh then
./scripts/run.sh (run.sh alone also works).

Stale test assumptions fixed so the suite is green again: test-gfx
waited for "gfx: check" while the shell prints "gfx check: PASS";
test-mouse/test-msg hardcoded msgrecv = task 3 (wm-input took slot 3 —
ids are parsed from the log now); the queue-full probe targeted task 0,
whose exec pump drains its own queue as completion codes (moved to the
cursor task, which never recvs).

Verified in QEMU: make test -> test-disk, test-gfx, test-mouse,
test-msg, test-fault all PASS.

1 files changed, 49 insertions, 0 deletions

diff --git a/scripts/build.sh b/scripts/build.sh
new file mode 100755
index 0000000..71430a4
--- /dev/null
+++ b/scripts/build.sh
@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+#
+# scripts/build.sh — compile the kernel and every external binary.
+#
+# The only cargo invocation in the project.  One pass builds the kernel
+# (rsdos.efi) and all /bin binaries (bins/*.efi), which is exactly what
+# the system image stages.
+#
+# Usage:
+#   ./scripts/build.sh            release (default — what the image uses)
+#   ./scripts/build.sh --debug    debug profile (slower guest, GDB symbols)
+#   ./scripts/build.sh --help
+#
+# Output:
+#   target/x86_64-unknown-uefi/<profile>/rsdos.efi   kernel
+#   target/x86_64-unknown-uefi/<profile>/<name>.efi  /bin binaries
+#
+# Typical flow:
+#   ./scripts/build.sh && ./scripts/run.sh
+#
+set -euo pipefail
+
+usage() {
+        awk 'NR > 1 && /^#/ { sub(/^# ?/, ""); print; next } NR > 1 { exit }' "$0"
+}
+
+# PROFILE is read by lib.sh (it derives OUT_DIR/KERNEL from it), so parse
+# before sourcing.
+while [ $# -gt 0 ]; do
+        case "$1" in
+        --debug) PROFILE="debug" ;;
+        --release) PROFILE="release" ;;
+        --help | -h)
+                usage
+                exit 0
+                ;;
+        *)
+                echo "build.sh: unknown argument: $1" >&2
+                exit 1
+                ;;
+        esac
+        shift
+done
+
+# shellcheck source=lib.sh
+source "$(dirname "$0")/lib.sh"
+
+build_all
+echo "kernel: $KERNEL"