fix(voice/consistency): vary stock formulas, vendor-balance orient.py, unify the loop

- Vary 11 instances of two boilerplate openers ("A generic X course…" /
  "Strip away X…") across 10 modules so they read as distinct, concrete prose;
  kept the few deliberate, voice-distinct uses; locked exemplars untouched.
- M23 orient.py: detect a vendor-balanced set of AI-instruction filenames
  (AGENTS.md/CLAUDE.md/GEMINI.md/.cursorrules/.cursor/rules/copilot-instructions)
  instead of singling out one vendor. Still runs.
- Render the collaboration loop consistently as seven stations
  (issue->branch->implementation->PR->review->merge->closed) in M25/M26 to match
  M11 and the syllabus.

Closes #48
Closes #49
Closes #51

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

modules/16-containers-and-reproducible-environments/README.md

@@ -137,8 +137,7 @@ run identically — laptop, pipeline, production.
 
 ## The AI angle
 
-A generic devops course teaches Docker the same way. What makes containers matter *more* in
-AI-assisted work:
+Docker itself you may already know. What makes containers matter *more* in AI-assisted work:
 
 - **AI writes code for an environment it can't see.** The model assumes packages are installed, a
   certain runtime version, paths that exist on *its* imagined machine. "Works on my machine"