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/15-security-scanning/README.md

@@ -181,7 +181,7 @@ CI, so there's one source of truth for "what counts as a finding."
 
 ## The AI angle
 
-A generic DevSecOps course teaches these three gates too. What makes them *load-bearing* here is that
+These three gates exist in any DevSecOps practice. What makes them *load-bearing* here is that
 AI-assisted coding doesn't just fail to prevent these problems — it actively manufactures all three,
 and does it in the exact form that slips past a human skim and a green build: