rename: IAMROOT → SKELETONKEY across the entire project

Breaking change. Tool name, binary name, function/type names,
constant names, env vars, header guards, file paths, and GitHub
repo URL all rebrand IAMROOT → SKELETONKEY.

Changes:
  - All "IAMROOT" → "SKELETONKEY" (constants, env vars, enum
    values, docs, comments)
  - All "iamroot" → "skeletonkey" (functions, types, paths, CLI)
  - iamroot.c → skeletonkey.c
  - modules/*/iamroot_modules.{c,h} → modules/*/skeletonkey_modules.{c,h}
  - tools/iamroot-fleet-scan.sh → tools/skeletonkey-fleet-scan.sh
  - Binary "iamroot" → "skeletonkey"
  - GitHub URL KaraZajac/IAMROOT → KaraZajac/SKELETONKEY
  - .gitignore now expects build output named "skeletonkey"
  - /tmp/iamroot-* tmpfiles → /tmp/skeletonkey-*
  - Env vars IAMROOT_MODPROBE_PATH etc. → SKELETONKEY_*

New ASCII skeleton-key banner (horizontal key icon + ANSI Shadow
SKELETONKEY block letters) replaces the IAMROOT banner in
skeletonkey.c and README.md.

VERSION: 0.3.1 → 0.4.0 (breaking).

Build clean on Debian 6.12.86. `skeletonkey --version` → 0.4.0.
All 24 modules still register; no functional code changes — pure
rename + banner refresh.

core/registry.h

@@ -1,44 +1,44 @@
 /*
- * IAMROOT — module registry
+ * SKELETONKEY — module registry
  *
  * Global list of registered modules. Each family contributes via
- * register_<family>_modules() called from iamroot main() at startup.
+ * register_<family>_modules() called from skeletonkey main() at startup.
  */
 
-#ifndef IAMROOT_REGISTRY_H
-#define IAMROOT_REGISTRY_H
+#ifndef SKELETONKEY_REGISTRY_H
+#define SKELETONKEY_REGISTRY_H
 
 #include "module.h"
 
-void iamroot_register(const struct iamroot_module *m);
+void skeletonkey_register(const struct skeletonkey_module *m);
 
-size_t iamroot_module_count(void);
-const struct iamroot_module *iamroot_module_at(size_t i);
+size_t skeletonkey_module_count(void);
+const struct skeletonkey_module *skeletonkey_module_at(size_t i);
 
 /* Find a module by name. Returns NULL if not found. */
-const struct iamroot_module *iamroot_module_find(const char *name);
+const struct skeletonkey_module *skeletonkey_module_find(const char *name);
 
 /* Each module family declares one of these in its public header. The
- * top-level iamroot main() calls them in order at startup. */
-void iamroot_register_copy_fail_family(void);
-void iamroot_register_dirty_pipe(void);
-void iamroot_register_entrybleed(void);
-void iamroot_register_pwnkit(void);
-void iamroot_register_nf_tables(void);
-void iamroot_register_overlayfs(void);
-void iamroot_register_cls_route4(void);
-void iamroot_register_dirty_cow(void);
-void iamroot_register_ptrace_traceme(void);
-void iamroot_register_netfilter_xtcompat(void);
-void iamroot_register_af_packet(void);
-void iamroot_register_fuse_legacy(void);
-void iamroot_register_stackrot(void);
-void iamroot_register_af_packet2(void);
-void iamroot_register_cgroup_release_agent(void);
-void iamroot_register_overlayfs_setuid(void);
-void iamroot_register_nft_set_uaf(void);
-void iamroot_register_af_unix_gc(void);
-void iamroot_register_nft_fwd_dup(void);
-void iamroot_register_nft_payload(void);
+ * top-level skeletonkey main() calls them in order at startup. */
+void skeletonkey_register_copy_fail_family(void);
+void skeletonkey_register_dirty_pipe(void);
+void skeletonkey_register_entrybleed(void);
+void skeletonkey_register_pwnkit(void);
+void skeletonkey_register_nf_tables(void);
+void skeletonkey_register_overlayfs(void);
+void skeletonkey_register_cls_route4(void);
+void skeletonkey_register_dirty_cow(void);
+void skeletonkey_register_ptrace_traceme(void);
+void skeletonkey_register_netfilter_xtcompat(void);
+void skeletonkey_register_af_packet(void);
+void skeletonkey_register_fuse_legacy(void);
+void skeletonkey_register_stackrot(void);
+void skeletonkey_register_af_packet2(void);
+void skeletonkey_register_cgroup_release_agent(void);
+void skeletonkey_register_overlayfs_setuid(void);
+void skeletonkey_register_nft_set_uaf(void);
+void skeletonkey_register_af_unix_gc(void);
+void skeletonkey_register_nft_fwd_dup(void);
+void skeletonkey_register_nft_payload(void);
 
-#endif /* IAMROOT_REGISTRY_H */
+#endif /* SKELETONKEY_REGISTRY_H */