Convert sfo.py and pkg.py to pure C

[bucanero]

Replaces the Python sfo.py and pkg.py PS3 toolchain utilities with standalone C implementations that produce identical output and accept the same CLI parameters. Eliminates the Python runtime dependency for SDK builds.

New files

• tools/ps3py/sfo.c — SFO create/inspect/XML-roundtrip (--fromxml, --toxml, -l, --title, --appid, -d, -p)
• tools/ps3py/pkg.c — PKG pack/list/extract (-c, -l, -x, -d); implements big-endian PKG format, SHA1 QA digest, stream-cipher encryption, and NPDRM SELF header injection
• tools/ps3py/sha1.c / sha1.h — SHA1 implementation carried over from the fself tool

Modified files

• tools/ps3py/Makefile — adds sfo and pkg build targets; install deploys C binaries instead of Python scripts
• ppu_rules — SFO := sfo.py → SFO := sfo, PKG := pkg.py → PKG := pkg

Bugs fixed vs. the Python originals

• Double-slash path construction (collect_dir): snprintf("%s/%s", folder, name) with a trailing-slash folder (as ppu_rules passes) produced folder//name, giving all filenames a leading /. This broke USRDIR/EBOOT.BIN NPDRM SELF detection and caused incorrect 32-byte name alignment for that entry instead of 16.
• Print-after-free (pack_pkg): Package Size and Data Size in stdout output always printed 0 because buf.size was read after dynbuf_free().

[bucanero]

Tested and both tools provide the same output as the original python scripts.

pkg packing example:

pkg.py --contentid=UP0001-NP0APOLLO_00-0000000000000000 testapp/ out.pkg

[X] Magic: 7f504b47
[X] Type: 00000001
[X] Offset to package info: 000000c0
[ ] unk1: 00000005
[X] Head Size: 00000080
[X] Item Count: 00000008
[X] Package Size: 00000000005973d0
[X] Data Offset: 0000000000000140
[X] Data Size: 0000000000597230
[X] ContentID: 'UP0001-NP0APOLLO_00-0000000000000000'
[X] QA_Digest: 9E8B76E5F357FFB66B2C8A5B81ECE1F8
[X] K Licensee: 00000000000000000000000000000000

output from pkg C tool:

pkg --contentid=UP0001-NP0APOLLO_00-0000000000000000 testapp/ out.pkg

[X] Magic: 7f504b47
[X] Type: 00000001
[X] Offset to package info: 000000c0
[ ] unk1: 00000005
[X] Head Size: 00000080
[X] Item Count: 00000008
[X] Package Size: 00000000005973d0
[X] Data Offset: 0000000000000140
[X] Data Size: 0000000000597230
[X] ContentID: 'UP0001-NP0APOLLO_00-0000000000000000'
[X] QA_Digest: 9E8B76E5F357FFB66B2C8A5B81ECE1F8
[X] K Licensee: 00000000000000000000000000000000