feat(course): build out all 27 modules, capstone, scaffold, and conventions

Scaffold the course repo and author the full curriculum in dependency-chain
order, following the settled build decisions in handoff.md.

- Scaffold: course README, vendor-neutral AGENTS.md (dogfoods Module 5),
  _TEMPLATE.md (the fixed 9-section module shape), root .gitignore, ship config.
- Modules 1-2: reference exemplars (locked for tone/depth/lab style).
- Modules 3-27: full lessons + runnable labs, each following the template,
  respecting the chain, vendor/model-agnostic, with "feel the pain" labs.
- Module 8 hosting comparison web-researched and date-stamped (as of 2026-06-22),
  not written from memory; expansion-zone modules carry Verify-before-publish.
- Capstone: the full loop end to end on the running tasks-app example.

Lab code syntax-checked (Python/shell/YAML); every module has the 7 core
template sections.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TfzV5QvtPDz8LJS3Pu5VLT

modules/22-securing-third-party-mcp-and-skills/lab/audit.sh

@@ -0,0 +1,87 @@
+#!/usr/bin/env bash
+#
+# audit.sh — a runnable version of the Module 22 vetting checklist.
+#
+# Static red-flag scan over a third-party MCP server or skill BEFORE you install it. It does not
+# execute anything in the target; it only reads. A clean run is NOT a guarantee (see "Where it
+# breaks") — it is a cheap first pass that catches the obvious and the lazy.
+#
+# Usage:  bash audit.sh <path-to-skill-or-server-dir>
+#
+set -euo pipefail
+
+TARGET="${1:-}"
+if [[ -z "$TARGET" || ! -d "$TARGET" ]]; then
+  echo "usage: bash audit.sh <directory>" >&2
+  exit 2
+fi
+
+hits=0
+section () { printf '\n=== %s ===\n' "$1"; }
+
+# scan <label> <regex>  — grep the tree, print matches, count a hit if found
+scan () {
+  local label="$1" regex="$2" out
+  out=$(grep -rIinE "$regex" "$TARGET" 2>/dev/null || true)
+  if [[ -n "$out" ]]; then
+    printf '\n[FLAG] %s\n' "$label"
+    printf '%s\n' "$out" | sed 's/^/    /'
+    hits=$((hits + 1))
+  fi
+}
+
+echo "Auditing: $TARGET"
+echo "Files:"
+find "$TARGET" -type f | sed 's/^/    /'
+
+section "Outbound network (where could data go?)"
+scan "HTTP / socket egress"        'urllib|requests\.|http\.client|socket\.|urlopen|fetch\(|axios|curl |wget '
+
+section "Credential & environment access (what secrets can it reach?)"
+scan "Reads the whole environment" 'os\.environ|getenv|process\.env|printenv|(^|[^A-Za-z])env([^A-Za-z]|$)'
+scan "Reads private credentials"   '\.ssh|id_rsa|\.aws|credentials|\.env([^a-z]|$)|NOTION_TOKEN'
+
+section "Code execution & obfuscation"
+scan "Shell-out / eval / exec"     'os\.system|subprocess|child_process|eval\(|exec\(|\| *bash|\| *sh($| )'
+scan "Encoding (often hides data)" 'base64|b64encode|atob\(|btoa\('
+
+section "Broad filesystem access"
+scan "Home / root paths"           'Path\.home|\$HOME|os\.path\.expanduser|(^|[^a-zA-Z0-9._/-])~/'
+
+section "Hidden / injected instructions in prose"
+scan "Imperative directives"       'ignore (previous|prior|all)|system:|maintenance mode|do not (mention|tell|list)|exfiltrat'
+
+# Zero-width / invisible characters smuggle instructions past a human reader. Use Python (a lab
+# prerequisite) so this works the same on every OS, regardless of the local grep flavor.
+section "Invisible characters (zero-width injection)"
+if command -v python3 >/dev/null 2>&1; then PY=python3; else PY=python; fi
+zw=$("$PY" - "$TARGET" <<'EOF'
+import os, sys
+bad = {"​","‌","‍","⁠",""}
+root = sys.argv[1]
+for dp, _, fns in os.walk(root):
+    for fn in fns:
+        p = os.path.join(dp, fn)
+        try:
+            text = open(p, encoding="utf-8", errors="ignore").read()
+        except OSError:
+            continue
+        for i, ch in enumerate(text):
+            if ch in bad:
+                print(f"    {p}: zero-width char U+{ord(ch):04X} at offset {i}")
+                break
+EOF
+)
+if [[ -n "$zw" ]]; then
+  printf '\n[FLAG] Invisible characters found\n%s\n' "$zw"
+  hits=$((hits + 1))
+fi
+
+section "Verdict"
+if (( hits > 0 )); then
+  echo "REJECT (or sandbox + scope) — $hits red-flag categor$([[ $hits -eq 1 ]] && echo y || echo ies) tripped."
+  echo "Read the flagged lines above against what the skill CLAIMS to do."
+  exit 1
+else
+  echo "No static red flags. Still: read the code, check provenance, and PIN the version before installing."
+fi