feat: release notes for 0.1.8; archive 0.1.8 iso; bump version to 0.1.9

Cut the 0.1.8 release (native GCC/binutils port forming the Montauk SDK,
revamped MTK-based Installer, anti-aliased MTK rounded-rect frames,
vblank-synced double-buffered Intel GPU page flips, max windows raised
to 32, and various bug fixes, including the halved ISO size from no
longer nesting ramdisk.tar). Archive the 0.1.8 ISO, publish it to the
website, refresh release notes and the downloads page, and open the
0.1.9 dev cycle (apiVersion 10, BuildNo reset).

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

archives/releasenotes.txt

@@ -1,3 +1,43 @@
+MontaukOS 0.1.8 (July 18, 2026)
+    (71c66f803516558012be13ee38cb02a9a0ba476a)
+
+New
+====
+    * Ported GCC/G++ compilers and binutils (as, ld, ar) to MontaukOS, with a hosted libstdc++, forming the new Montauk SDK
+    * Installer redesigned on the MTK toolkit, with new software component selection
+    * MTK toolkit now anti-aliases rounded-rect frames (buttons, fields, panels)
+    * Intel GPU page flipping is now vblank-synced and double-buffered
+    * Max open desktop windows raised from 16 to 32
+
+Fixed
+=====
+    * The Files pathbar now qualifies paths
+    * Fixed Font Preview crash when opened manually
+    * Fixed inconsistent border radiuses on MTK UI elements
+    * Fixed Intel HDA audio controllers not being recognized
+    * Bluetooth A2DP audio output is now exclusive to one process, preventing playback conflicts
+    * Fixed a desktop/Files app freeze when deleting large files
+    * Roughly halved the ISO size by no longer embedding a redundant copy of the ramdisk
+
+Included in ISO
+================
+
+    * MontaukOS SMP kernel
+    * Userspace bootstrap (0:/os/init.elf) and other essential system utilities
+    * MontaukOS desktop environment and graphical apps
+    * Manual pages (0:/man), readable via man command
+    * System CA certificates (0:/os/certs/ca-certificates.crt)
+    * Intel Bluetooth controller firmware (0:/os/firmware/intel)
+    * Third-party license texts and notices (0:/os/licenses)
+    * Tiny C Compiler (tcc) with MontaukOS headers and libraries (0:/lib/tcc)
+    * Lua 5.4 interpreter (lua) with headers and static library (0:/lib/lua)
+    * Montauk SDK - native GCC/G++ and binutils (0:/sdk), built via `make sdk`
+    * Flat Remix icon pack
+    * JetBrains Mono, Noto Serif, Roboto, and C059 Roman (open Century Schoolbook) TrueType fonts
+    * DOOM engine with SDL_mixer audio support (game data not included)
+    * Experimental HTTP server (httpd) and default page (0:/www/index.html)
+    * Default wallpaper - blossoms by Nikhil Kumar, Unsplash (0:/os/wallpapers)
+
 MontaukOS 0.1.7 (July 9, 2026)
     (9b66d3f4703b9d4d19d1a7f37aff8d36fb076f7c)