style(no-slop): remove every em-dash + banned words across all modules + capstone

Apply the no-ai-slop standard (now binding in AGENTS.md): the em-dash character is
banned outright (restructured, not blind-replaced), plus the banned word/phrase
list (delve, leverage, robust, seamless, truly, unlock, etc.). 0 em-dashes remain
in modules + capstone; the only "robust" left is the planted M10 ai-change.patch
trap. Module H1 titles use a colon separator.

All deliberate teaching devices preserved; labs compile/parse (py/sh/yaml/json);
no junk. AGENTS.md updated with the hard no-slop rules.

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

modules/26-orchestrating-multiple-agents/lab/cleanup.sh

@@ -1,8 +1,8 @@
 #!/usr/bin/env bash
-# Module 26 lab — tear down the fleet after the work has merged.
+# Module 26 lab: tear down the fleet after the work has merged.
 #
 # Removes each worktree and prunes stale records. Refuses to remove a worktree with uncommitted
-# work (Git's safety) — commit or merge first. Run from inside your tasks-app repo.
+# work (Git's safety); commit or merge first. Run from inside your tasks-app repo.
 
 set -euo pipefail
 
@@ -17,7 +17,7 @@ git rev-parse --git-dir >/dev/null 2>&1 || { echo "not a git repo" >&2; exit 1;
 for path in "${FLEET[@]}"; do
   if [ -d "$path" ]; then
     echo "remove: $path"
-    git worktree remove "$path"   # fails if dirty — that's intentional; commit first
+    git worktree remove "$path"   # fails if dirty; that's intentional, commit first
   fi
 done