feat(python): drop configure-project-installer, inline autotools build

Switch fromsource:python (cpython) to its own inline autotools build,
applying the cluster-A sandbox-fix template. This is the last cluster B
leaf and exercises every other cluster-B fix end-to-end (zlib, openssl,
ncurses, readline, libffi, bzip2, xz-utils, util-linux/libuuid).

* paths derived from pkginfo.install_file() (path.absolute is nil)
* configure + make + install chained in single sh -c (os.cd doesn't
  propagate to system.exec children)
* fixed -j8
* deps: explicit xim:gcc + xim:make + xim:xpkg-helper (previously
  pulled in transitively via xim:configure-project-installer)
* license: humanized string -> SPDX PSF-2.0
* env exports kept inline in sh -c (TZDIR, CPPFLAGS, LDFLAGS) so they
  reach the configure subprocess; os.setenv at lua scope didn't reach
  configure's grandchildren via xpkg-helper indirection in the legacy
  flow.

CPPFLAGS / LDFLAGS extensions:
  -I<sysroot>/usr/include             core stdlib deps
  -I<sysroot>/usr/include/ncurses     for `<termcap.h>` / `<curses.h>`
                                      flat lookup (ncurses installs
                                      these under the ncurses/ subdir)
  -I<sysroot>/usr/include/openssl     for openssl 3 headers (some are
                                      under the openssl/ subdir)
  -L<sysroot>/lib                     find xvm-shimmed shared libs
  -Wl,-rpath,/home/xlings/.xlings_data/subos/linux/lib
                                      bake canonical xlings runtime
                                      lib path so the produced python
                                      binary loads its dependent
                                      shared libs from a user-machine
                                      install, not the build host

Configure flags:
  --enable-shared                     ship libpython3.13.so for embedders
  --with-computed-gotos               faster main loop dispatch
  --enable-ipv6                       IPv6 sockets
  --enable-loadable-sqlite-extensions ready for future fromsource:sqlite3
  --with-system-ffi                   link against fromsource:libffi

Verified end-to-end in xlings 0.4.9 iso (with cluster B 1..7 all
MERGED upstream as #62..#68):
  ✓ configure -> make -j8 -> make install (~1m20s with deps cached)
  ✓ produced bin/python3, bin/pip3, bin/idle3, bin/python3-config
  ✓ produced lib/libpython3.13.so.1.0
  ✓ python3 --version -> 3.13.1
  ✓ stdlib import sanity:
    - zlib    (zlib 1.3.1)
    - ssl     (OpenSSL 3.1.5 30 Jan 2024)
    - hashlib (sha256 round-trip)
    - lzma    (xz-utils via _lzma)
    - bz2     (bzip2)
    - uuid    (util-linux libuuid)
    - readline (8.2 patched series)
    - ctypes  (libffi)

_sqlite3 is intentionally skipped (no fromsource:sqlite3 yet — tracked
under the existing "TODO: gdbm, sqlite3, tk/tkinter" line in deps).

Cluster B leaf 8/8 — sweep complete. Net effect across cluster B:
`grep -lR configure-project-installer pkgs/` should now match zero.

Author: Sunrisepeak

pkgs/p/python.lua

@@ -1,4 +1,6 @@
-function _linux_download_url(version) return "https://www.python.org/ftp/python/" .. version .. "/Python-" .. version .. ".tar.xz" end
+function _linux_download_url(version)
+    return format("https://www.python.org/ftp/python/%s/Python-%s.tar.xz", version, version)
+end
 
 package = {
     spec = "1",
@@ -7,7 +9,7 @@ package = {
     name = "python",
     description = "The Python programming language",
     maintainers = "Python Software Foundation",
-    licenses = "PSF License | GPL compatible",
+    licenses = "PSF-2.0",
     repo = "https://github.com/python/cpython",
     docs = "https://docs.python.org/3",
 
@@ -26,9 +28,9 @@ package = {
     xpm = {
         linux = {
             deps = {
+                "xim:xpkg-helper@0.0.1",
                 "xim:gcc@15.1.0",
                 "xim:make@4.3",
-                "xim:configure-project-installer@0.0.1",
                 "fromsource:xz-utils@5.4.5",
                 "fromsource:libffi@3.4.4",
                 "fromsource:readline@8.2",
@@ -53,32 +55,59 @@ package = {
 import("xim.libxpkg.pkginfo")
 import("xim.libxpkg.system")
 import("xim.libxpkg.xvm")
+import("xim.libxpkg.log")
 
 local binding_tree = "python-binding-tree"
 
 function install()
-    local project_dir = path.absolute("Python-" .. pkginfo.version())
-    --  build args - opt or todo?
-        --enable-shared
-        --with-computed-gotos 
-        --with-lto
-        --enable-ipv6
-        --enable-loadable-sqlite-extensions
-    -- add rpath to fix: Following modules built successfully but were removed because they could not be imported:
-    local syslibdir = path.join(system.subos_sysrootdir(), "lib")
-    os.setenv("LDFLAGS", "-Wl,-rpath," .. syslibdir)
-    -- fix: test test_datetime failed (tzdata)
-    os.setenv("TZDIR", "/usr/share/zoneinfo")
-    system.exec("configure-project-installer "
-        .. pkginfo.install_dir()
-        .. " --project-dir " .. project_dir
-        --.. " --args " .. [["--enable-shared --enable-optimizations"]]
-    )
+    -- Sandbox template (PR #49 bzip2): derive paths from pkginfo.install_file()
+    -- since path.absolute is nil; chain configure + make + install in single
+    -- sh -c (os.cd doesn't propagate to system.exec children).
+    local runtime_dir = path.directory(pkginfo.install_file())
+    local scode_dir = path.join(runtime_dir, "Python-" .. pkginfo.version())
+    local build_dir = path.join(runtime_dir, "build-python")
+    local prefix = pkginfo.install_dir()
+    local sysroot = system.subos_sysrootdir()
+    local syslibdir = path.join(sysroot, "lib")
+
+    os.tryrm(build_dir)
+    os.mkdir(build_dir)
+
+    log.info("Configuring + building + installing python (autotools)...")
+    -- CPPFLAGS / LDFLAGS point at the subos sysroot where the cluster-B
+    -- deps (zlib, openssl, ncurses, readline, libffi, bzip2, xz-utils,
+    -- util-linux/libuuid) installed their headers + libs via xvm.add. The
+    -- extra -I .../usr/include/{ncurses,openssl} entries cover deps that
+    -- ship under a subdir.
+    -- LDFLAGS rpath points at the canonical /home/xlings/... so the produced
+    -- python binary loads its shared deps from the standard xlings install
+    -- layout on a user machine. TZDIR avoids test_datetime tzdata noise.
+    -- Configure flags:
+    --   --enable-shared:                    ship libpython3.so for embedders
+    --   --with-computed-gotos:              -fno-crossjumping main loop dispatch
+    --   --enable-ipv6:                      sockets v6
+    --   --enable-loadable-sqlite-extensions ready for future scode:sqlite3
+    --   --with-system-ffi:                  link against fromsource:libffi
+    --   --without-ensurepip:                pip is added separately by xvm
+    system.exec(string.format(
+        "sh -c 'cd %s && "
+        .. "CPPFLAGS=\"-I%s/usr/include -I%s/usr/include/ncurses -I%s/usr/include/openssl\" "
+        .. "LDFLAGS=\"-L%s/lib -Wl,-rpath,/home/xlings/.xlings_data/subos/linux/lib\" "
+        .. "TZDIR=/usr/share/zoneinfo "
+        .. "%s/configure --prefix=%s "
+        .. "--enable-shared --with-computed-gotos --enable-ipv6 "
+        .. "--enable-loadable-sqlite-extensions --with-system-ffi "
+        .. "&& make -j8 && make install'",
+        build_dir,
+        sysroot, sysroot, sysroot,
+        sysroot,
+        scode_dir, prefix
+    ))
+
     return os.isdir(pkginfo.install_dir())
 end
 
 function config()
-
     local python_bindir = path.join(pkginfo.install_dir(), "bin")
     local binding_root = binding_tree .. "@" .. pkginfo.version()
 
@@ -91,7 +120,7 @@ function config()
         envs = {
             TZDIR = "/usr/share/zoneinfo",
             -- python manim-test.py (need LD_LIBRARY_PATH to xlings subos lib)
-            -- ImportError: libstdc++.so.6: cannot open shared object file: No such file or directory
+            -- ImportError: libstdc++.so.6: cannot open shared object file
             LD_LIBRARY_PATH = path.join(system.subos_sysrootdir(), "lib"),
         }
     }
@@ -128,19 +157,16 @@ end
 
 --[[
 
-[ERROR] readline failed to import: /home/xlings/.xlings_data/subos/linux/lib/libreadline.so.8: undefined symbol: UP
-The following modules are *disabled* in configure script:
-_sqlite3                                                                   
-
-The necessary bits to build these optional modules were not found:
-_bz2                      _curses                   _curses_panel          
-_dbm                      _gdbm                     _tkinter               
-To find the necessary bits, look in configure.ac and config.log.
+Historical build-time notes:
 
-Following modules built successfully but were removed because they could not be imported:
-readline -- by patch to fix                                                                  
+  [ERROR] readline failed to import: ... undefined symbol: UP
+    -> fixed by readline-8.2 patch sequence (PR for readline)
 
-Checked 112 modules (33 built-in, 70 shared, 1 n/a on linux-x86_64, 1 disabled, 6 missing, 1 failed on import)
+  Optional modules that may be missing depending on what scode/fromsource
+  packages are installed:
 
+  _sqlite3
+  _bz2  _curses  _curses_panel  _dbm  _gdbm  _tkinter
 
-]]
+  Tracked under the "TODO: gdbm, sqlite3, tk/tkinter" line in deps.
+]]