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.

tools/skeletonkey-fleet-scan.sh

@@ -1,10 +1,10 @@
 #!/usr/bin/env bash
-# iamroot-fleet-scan — scan a host list with iamroot, aggregate results
+# skeletonkey-fleet-scan — scan a host list with skeletonkey, aggregate results
 #
 # Usage:
-#   iamroot-fleet-scan.sh [OPTIONS] hosts.txt
-#   iamroot-fleet-scan.sh [OPTIONS] -                       # hosts on stdin
-#   iamroot-fleet-scan.sh [OPTIONS] -                       # one host per line
+#   skeletonkey-fleet-scan.sh [OPTIONS] hosts.txt
+#   skeletonkey-fleet-scan.sh [OPTIONS] -                       # hosts on stdin
+#   skeletonkey-fleet-scan.sh [OPTIONS] -                       # one host per line
 #
 # Each line in the host list is either:
 #   - a hostname/IP (uses default ssh user from your config)
@@ -14,13 +14,13 @@
 # Output: combined JSON to stdout, one object per host:
 #   { "generated_at": "...", "summary": {...},
 #     "hosts": [ { "host": "...", "ok": true,
-#                  "scan": { /* iamroot --scan --json */ } }, ... ] }
+#                  "scan": { /* skeletonkey --scan --json */ } }, ... ] }
 #
 # Options:
-#   --binary <path>      path to iamroot binary (default: ./iamroot)
+#   --binary <path>      path to skeletonkey binary (default: ./skeletonkey)
 #   --ssh-key <path>     ssh key file (passed to scp and ssh)
 #   --ssh-opts "..."     extra ssh options (e.g. "-o ConnectTimeout=5")
-#   --remote-path <p>    where to scp the binary (default: /tmp/iamroot)
+#   --remote-path <p>    where to scp the binary (default: /tmp/skeletonkey)
 #   --no-sudo            don't prefix the remote command with sudo
 #   --parallel <N>       run N hosts concurrently (default: 4)
 #   --summary-only       skip per-host detail in stdout; print summary only
@@ -32,10 +32,10 @@
 
 set -euo pipefail
 
-BINARY="./iamroot"
+BINARY="./skeletonkey"
 SSH_KEY=""
 SSH_OPTS=""
-REMOTE_PATH="/tmp/iamroot"
+REMOTE_PATH="/tmp/skeletonkey"
 USE_SUDO=1
 PARALLEL=4
 SUMMARY_ONLY=0
@@ -66,7 +66,7 @@ if [[ -z "$HOSTFILE" ]]; then
 fi
 
 if [[ ! -x "$BINARY" ]]; then
-    echo "error: iamroot binary not found / not executable: $BINARY" >&2
+    echo "error: skeletonkey binary not found / not executable: $BINARY" >&2
     exit 2
 fi
 
@@ -109,7 +109,7 @@ scan_one_host() {
     fi
 
     # 2. run --scan --json
-    # iamroot's exit codes are SEMANTIC (0=OK, 2=VULNERABLE, 4=PRECOND_FAIL, etc.)
+    # skeletonkey's exit codes are SEMANTIC (0=OK, 2=VULNERABLE, 4=PRECOND_FAIL, etc.)
     # — nonzero is NOT a failure here. Treat ANY stdout JSON as success;
     # only ssh-transport-level failures (key denied, network) are real
     # failures, and those manifest as empty stdout + nonzero exit.
@@ -133,7 +133,7 @@ scan_one_host() {
     # 4. emit one combined JSON object
     if ! echo "$scan_out" | jq --arg h "$hostspec" \
             '{host: $h, ok: true, scan: .}' 2>/dev/null; then
-        echo "{\"host\":\"${hostspec}\",\"ok\":false,\"error\":\"invalid JSON from iamroot\"}"
+        echo "{\"host\":\"${hostspec}\",\"ok\":false,\"error\":\"invalid JSON from skeletonkey\"}"
         return 1
     fi
 }