optimize images and add deploy-html target

- resize all images to max 1920px width (152MB → 66MB)
- add assets-original/ to gitignore for backups
- add make optimize-images target
- add make deploy-html for faster HTML-only deployment

.gitignore

@@ -63,3 +63,4 @@ Desktop.ini
 *.pdf
 index.md.bak
 hdm-lehrauftrag-uebersicht.md
+slides/assets-original/

Makefile

@@ -1,6 +1,6 @@
 # Makefile for Marp Slides Project
 
-.PHONY: help build dev watch pdf html clean install deploy copy-assets
+.PHONY: help build dev watch pdf html clean install deploy deploy-html copy-assets optimize-images
 
 # Directories
 SLIDES_DIR = slides
@@ -27,10 +27,14 @@ help:
 	@echo "    make pdf        - Export all slides to PDF"
 	@echo "    make html       - Export all slides to HTML"
 	@echo ""
+	@echo "  Deploy:"
+	@echo "    make deploy     - Full build + deploy (HTML, PDF, assets)"
+	@echo "    make deploy-html - HTML only deploy (faster)"
+	@echo ""
 	@echo "  Other:"
+	@echo "    make optimize-images - Resize images to max 1920px"
 	@echo "    make clean      - Remove generated files"
 	@echo "    make install    - Install dependencies"
-	@echo "    make deploy     - Deploy slides to server"
 
 # Ensure build directory exists
 $(BUILD_DIR)/.exists:
@@ -91,7 +95,18 @@ install:
 	@echo "Installing dependencies..."
 	npm install
 
-# Deploy slides
+# Optimize images (resize to max 1920px, requires nix-shell -p imagemagick)
+optimize-images:
+	@echo "Backing up originals to assets-original/..."
+	@mkdir -p $(SLIDES_DIR)/assets-original
+	@cp $(SLIDES_DIR)/assets/*.png $(SLIDES_DIR)/assets-original/ 2>/dev/null || true
+	@cp $(SLIDES_DIR)/assets/*.jpg $(SLIDES_DIR)/assets-original/ 2>/dev/null || true
+	@echo "Resizing images to max 1920px..."
+	@nix-shell -p imagemagick --run 'for img in $(SLIDES_DIR)/assets/*.png; do magick "$$img" -resize "1920x>" -quality 85 "$$img"; done'
+	@nix-shell -p imagemagick --run 'for img in $(SLIDES_DIR)/assets/*.jpg; do magick "$$img" -resize "1920x>" -quality 85 "$$img"; done'
+	@echo "Done! Originals backed up in assets-original/"
+
+# Deploy slides (full build)
 deploy: build
 	@echo "Deploying slides..."
 	@echo "Copying HTML files..."
@@ -100,3 +115,10 @@ deploy: build
 	scp -r $(BUILD_DIR)/assets/ tengo@tuttle.uberspace.de:/home/tengo/html/hdm/223015b/
 	@echo "Copying materials..."
 	scp -r $(BUILD_DIR)/materials/ tengo@tuttle.uberspace.de:/home/tengo/html/hdm/223015b/ 2>/dev/null || true
+
+# Deploy HTML only (faster, no PDF rebuild)
+deploy-html: html
+	@echo "Deploying HTML only..."
+	scp $(BUILD_DIR)/*.html tengo@tuttle.uberspace.de:/home/tengo/html/hdm/223015b/
+	scp -r $(BUILD_DIR)/assets/ tengo@tuttle.uberspace.de:/home/tengo/html/hdm/223015b/
+	scp -r $(BUILD_DIR)/materials/ tengo@tuttle.uberspace.de:/home/tengo/html/hdm/223015b/ 2>/dev/null || true