feat: redesign installer on MTK toolkit with component selection

Rewrite the Installer app on the Montauk Toolkit (Canvas + gui/mtk
widgets, theme, hover states, scrollbar) replacing the hand-rolled px_*
renderer and bespoke TrueType usage.

Add a new "Software" step: an expandable checkbox tree for optional
components (Montauk SDK with gcc/g++, binutils, tcc, lua sub-items;
Games; Office; Internet apps; Printing; experimental httpd and SDR).
Unchecked components' paths are excluded from the install copy, with a
longest-path ownership rule so e.g. sdk/tcc installs even when the rest
of the SDK is deselected. The update flow refreshes only the components
the target already has.

Add tri-state checkbox and disclosure-arrow widgets to the MTK toolkit
(anti-aliased, supersampled).

Merge tcc and lua into 0:/sdk (0:/sdk/tcc, 0:/sdk/lua) and drop 0:/lib:
update tcc config.h, lua luaconf.h, both Makefiles, the devkit clean
scope, man pages and montaukos.org notices.

Make printing optional: init skips printd when 0:/os/printd.elf is
absent.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

programs/src/init/main.cpp

@@ -124,6 +124,13 @@ static void log_err(const char* msg)  { log(LOG_ERR, msg); }
 
 // ---- Service runner ----
 
+static bool service_installed(const char* path) {
+    int fd = montauk::open(path);
+    if (fd < 0) return false;
+    montauk::close(fd);
+    return true;
+}
+
 static bool run_service(const char* path, const char* name, bool wait = true) {
     char msg[128];
 
@@ -156,7 +163,12 @@ extern "C" void _start() {
 
     // ---- Stage 1: Network configuration (non-blocking) ----
     run_service("0:/os/dhcp.elf", "dhcp", false);
-    run_service("0:/os/printd.elf", "print spooler", false);
+
+    // Printing is an optional install component; skip quietly when absent.
+    if (service_installed("0:/os/printd.elf"))
+        run_service("0:/os/printd.elf", "print spooler", false);
+    else
+        log_info("Print spooler not installed, skipping");
 
     // ---- Stage 2: Login screen -> desktop (falls back to desktop, then shell) ----
     if (!run_service("0:/os/login.elf", "login")) {