provision: add ccrypt, nodejs, claude, ssh identity keys, fix scons obj dirs

- Install ccrypt, nodejs 18, npm, claude code in provision
- Decrypt id_rsa/id_rsa.pub via dongle ID and install to /data/ssh/.ssh/
- Run provision directly instead of through qt_shell wrapper
- Fix panda and body SConscripts to mkdir obj/ before writing gitversion.h
- Add sudo to su - comma build call
- Remount / rw at top of provision

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

body/board/SConscript

@@ -121,6 +121,7 @@ def objcopy(source, target, env, for_signature):
     return '$OBJCOPY -O binary %s %s' % (source[0], target[0])
 
 # Common autogenerated includes
+os.makedirs("obj", exist_ok=True)
 git_ver = get_version(BUILDER, BUILD_TYPE)
 with open("obj/gitversion.h", "w") as f:
   f.write(f'const uint8_t gitversion[8] = "{git_ver}";\n')