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/06-branches-sandboxes-for-experiments/lab/make-conflict.sh

@@ -1,11 +1,11 @@
 #!/usr/bin/env bash
 #
-# make-conflict.sh — manufacture a guaranteed merge conflict to practice on.
+# make-conflict.sh: manufacture a guaranteed merge conflict to practice on.
 #
 # AI edits are nondeterministic, so the lab's organic conflict (two branches editing the same usage
 # line in cli.py) doesn't ALWAYS land. This script guarantees one: it creates two branches that each
 # append a different line to the same spot in README.md, then leaves you mid-merge with a real
-# conflict in your working tree. The resolution mechanic is identical to the code case in the lab —
+# conflict in your working tree. The resolution mechanic is identical to the code case in the lab:
 # read the <<<<<<< / ======= / >>>>>>> markers, edit to the version you want, remove the markers,
 # then `git add` + `git commit`.
 #