feat: elearning_agent — reduce tools 14 → 8 so it registers at startup

- Merge get_course_stats + get_enrolled_users + get_slide_completion → get_course_details
- Fold publish_course into update_course via website_published param
- Drop flag_low_completion (replaced by post_chatter_note) and suggest_next_course
  (still callable internally via peer-bus suggest_courses request)
- elearning_tools: add get_course_details(), extend update_course() signature
- ARCHITECTURE.md: mark elearning_agent as registered

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ARCHITECTURE.md

@@ -216,8 +216,12 @@ Each agent follows the same lifecycle: `execute()` → `_plan()` → `_act()`
 | `employees_agent` | `hr.employee`, `hr.leave` | Headcount, leave, HR queries |
 | `odoo_doc_agent` | RAG (Qdrant) | Odoo documentation Q&A |
 
-**`elearning_agent`** — defined but not registered: exceeds the 8-tool limit per
-agent. Needs to be split into contextual tool groups before it can be used.
+**`elearning_agent`** — registered. Reduced from 14 → 8 tools by merging the three
+per-course read calls (`get_course_stats`, `get_enrolled_users`, `get_slide_completion`)
+into `get_course_details`, folding `publish_course` into `update_course` via a
+`website_published` param, and dropping `flag_low_completion` (superseded by
+`post_chatter_note`) and `suggest_next_course` (still available internally via the
+peer-bus `suggest_courses` request).
 
 ---