restructure: rename termin to kapitel, flatten folder structure

- rename slide files: YYYY-MM-DD-termin-N-topic.md → NN-topic.md
- flatten folders: courses/X/slides/ → slides/X/
- replace "Termin" with "Kapitel" in all content
- add klausur extraction script (make klausur)
- update Makefile, generate-index.sh, dev-server.sh
- add README.md with full documentation

CLAUDE.md

@@ -4,8 +4,8 @@ This project builds presentation decks for Marp, supporting multiple courses.
 
 ## Courses
 
-- **223015b** - Dateiformate, Schnittstellen, Speichermedien (6 Termine)
-- **223015c** - Internettechnologien (3 Termine)
+- **223015b** - Dateiformate, Schnittstellen, Speichermedien (6 Kapitel)
+- **223015c** - Internettechnologien (3 Kapitel)
 
 ## Agent Restrictions
 
@@ -15,7 +15,7 @@ This project builds presentation decks for Marp, supporting multiple courses.
 
 ## Critical File Protection
 
-Slide files in `courses/*/slides/*.md` are main content files:
+Slide files in `slides/*/*.md` are main content files:
 - ALLOWED: Adding slides, adjusting content, fixing typos, enhancing sections
 - FORBIDDEN (without permission): Deleting slides, removing sections, bulk deletions
 - Before ANY deletion: ALWAYS ask user for confirmation
@@ -23,9 +23,9 @@ Slide files in `courses/*/slides/*.md` are main content files:
 ## Project Structure
 
 ```
-courses/
-├── 223015b/slides/     # Dateiformate course
-└── 223015c/slides/     # Internettechnik course
+slides/
+├── 223015b/            # Dateiformate course
+└── 223015c/            # Internettechnik course
 scripts/                # Shared scripts
 themes/                 # Custom Marp themes
 build/                  # Generated output (gitignored)
@@ -34,13 +34,14 @@ build/                  # Generated output (gitignored)
 ## Build Commands
 
 ```bash
-make dev-b          # Dev server 223015b (port 1312)
-make dev-c          # Dev server 223015c (port 1313)
+make dev-b          # Dev server 223015b (port 1311)
+make dev-c          # Dev server 223015c (port 1312)
 make build          # Build all courses
 make build-b        # Build 223015b only
 make build-c        # Build 223015c only
 make html           # HTML only
 make pdf            # PDF only
+make klausur        # Extract klausur slides → slides/*/klausur.md
 make deploy         # Deploy all (ASK FIRST!)
 ```
 
@@ -56,12 +57,12 @@ nix run .#optimize-img -- <path>      # Optimize images
 ## Code Style Guidelines
 
 ### File Structure
-- Slides in `courses/<course>/slides/`
-- Assets in `courses/<course>/slides/assets/`
+- Slides in `slides/<course>/`
+- Assets in `slides/<course>/assets/`
 - Always reference images as `./assets/filename.png`
 
 ### Naming Conventions
-- Slide files: `YYYY-MM-DD-termin-N-topic.md`
+- Slide files: `NN-topic.md` (e.g., `01-grundlagen.md`)
 - Images: `snake_case.jpg` or `kebab-case.jpg`
 
 ### Markdown Style