Introduce #include <cosmo.h> to toolchain users

This change improves the way internal APIs are being hidden behind the
`COSMO` define. The cosmo.h header will take care of defining that, so
that a separate define statement isn't needed. This change also does a
lot more to define which APIs are standard, and which belong to Cosmo.

tool/decode/lib/zipnames.c

@@ -17,7 +17,7 @@
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/nt/enum/fileflagandattributes.h"
-#include "libc/zip.h"
+#include "libc/zip.internal.h"
 #include "tool/decode/lib/zipnames.h"
 
 const struct IdName kZipCompressionNames[] = {

tool/decode/scrubdox.c

@@ -70,10 +70,10 @@
    ├────────────┼─────────────┼────────────────────────────────┼────────────┤
    │   [ ? ]    │    About    │ this page                      │            │
    └────────────┴─────────────┴────────────────────────────────┴────────────┘ */
-#include "libc/log/log.h"
 #include "libc/macros.internal.h"
 #include "libc/mem/gc.h"
 #include "libc/mem/mem.h"
+#include "libc/runtime/runtime.h"
 #include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
 #include "libc/str/strwidth.h"

tool/decode/zip.c

@@ -16,7 +16,7 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/zip.h"
+#include "libc/zip.internal.h"
 #include "libc/calls/calls.h"
 #include "libc/calls/struct/stat.h"
 #include "libc/fmt/conv.h"

tool/decode/zip2.c

@@ -30,7 +30,7 @@
 #include "libc/sysv/consts/prot.h"
 #include "libc/x/xasprintf.h"
 #include "libc/x/xiso8601.h"
-#include "libc/zip.h"
+#include "libc/zip.internal.h"
 #include "tool/decode/lib/asmcodegen.h"
 #include "tool/decode/lib/disassemblehex.h"
 #include "tool/decode/lib/zipnames.h"