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/01-the-copy-paste-problem/lab/starter/README.md

@@ -1,7 +1,7 @@
-# Demo app — `tasks`
+# Demo app: `tasks`
 
 A deliberately tiny command-line task tracker. It exists to be *changed by an AI*, so it's small
-enough to read in a minute but real enough to have more than one file — which is exactly where the
+enough to read in a minute but real enough to have more than one file, which is exactly where the
 copy-paste workflow starts to hurt.
 
 This is the running example for **Module 1** (where you feel the copy-paste problem) and **Module 2**
@@ -9,8 +9,8 @@ This is the running example for **Module 1** (where you feel the copy-paste prob
 
 ## Files
 
-- `tasks.py` — the core logic (`Task`, `TaskList`).
-- `cli.py` — the command-line front end. Reads/writes `tasks.json`.
+- `tasks.py`: the core logic (`Task`, `TaskList`).
+- `cli.py`: the command-line front end. Reads/writes `tasks.json`.
 
 ## Run it