MachO: adjust __init_offsets when add_section shifts __TEXT

[je-empty]

add_section into __TEXT shifts the following content via Binary::shift, but shift doesn't update the image-base offsets stored in __TEXT,__init_offsets (S_INIT_FUNC_OFFSETS). They keep pointing at the old location, so dyld jumps into the wrong place and the binary crashes at launch (SIGILL). The fix bumps each entry past the shift point.

b = lief.MachO.parse("app").at(0)   # app has a constructor -> __init_offsets
b.add_section(lief.MachO.Section.create("__mysec", [0x41] * 0x4000))  # into __TEXT
b.write("out")   # SIGILLs on launch without the fix, runs with it

The constructor offset stays 0x4b0 while the code moves to 0x44b0; a section too small to force a shift is unaffected. Verified on macOS arm64 and an iPhone Air (iOS 26.6). Closes #1229.

[je-empty]

Superseded by #1369 — same fix, clean single-commit history.