Fix archetype routing and narrow build sentinel dependencies

- Move Rmd archetype from _default/ to rmarkdown/ so hugo-new.sh's
  --kind rmarkdown resolves to the correct archetype instead of
  working by accident via file extension fallback
- Replace broad content/*/* glob in .build_sentinel with explicit
  find for content (.md, .html, images), layouts, and hugo.yaml
- Fix typo in Makefile comment ("my" -> "by")

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Makefile

@@ -100,11 +100,15 @@ LIBS_URL := /libs
 #
 #-----------------------------------------------------------------------------#
 
-.build_sentinel: $(MD_TARGETS) $(wildcard content/*/*)
+# Rebuild when rendered Rmd targets, markdown, or page bundle assets change
+CONTENT_FILES := $(shell find content -name '*.md' -o -name '*.html' -o -name '*.svg' -o -name '*.png' -o -name '*.jpg' | grep -v '*~')
+LAYOUT_FILES  := $(shell find layouts -name '*.html' | grep -v '*~')
+
+.build_sentinel: $(MD_TARGETS) $(CONTENT_FILES) $(LAYOUT_FILES) hugo.yaml
 	@echo "\t 🏗️ Building site"
 	@# We call hugo with two options:
 	@#  --cleanDestinationDir, to remove deleted files
-	@#  --minify, to compress files my removing extra whitespace
+	@#  --minify, to compress files by removing extra whitespace
 	hugo --cleanDestinationDir --minify
 	@touch $@
 	@echo "✓ Building complete"

hugo-new.sh

@@ -18,11 +18,15 @@ fi
 KIND="$1"  # post or rmarkdown
 TITLE="$2"
 
-# Validate post type
-if [[ "$KIND" != "post" && "$KIND" != "rmarkdown" ]]; then
-    echo "Error: Type must be 'post' or 'rmarkdown'."
-    exit 1
-fi
+# Validate post type and set file extension
+case "$KIND" in
+    post)      EXT="md" ;;
+    rmarkdown) EXT="Rmd" ;;
+    *)
+        echo "Error: Type must be 'post' or 'rmarkdown'."
+        exit 1
+        ;;
+esac
 
 # Generate ISO date prefix (YYYY-MM-DD)
 DATE=$(date +"%Y-%m-%d")
@@ -33,15 +37,6 @@ SLUG=$(echo "$TITLE" | tr '[:upper:]' '[:lower:]' | tr ' ' '-')
 # Construct post directory
 POST_DIR="content/posts/${DATE}-${SLUG}"
 
-# Determine the expected file extension
-EXT="md"
-if [[ "$KIND" == "rmarkdown" ]]; then
-    EXT="Rmd"
-fi
-
-# Ensure the directory exists and create a page bundle
-mkdir -p "$POST_DIR"
-
 # Generate the new post with the selected archetype
 hugo new --kind "$KIND" "posts/${DATE}-${SLUG}/index.${EXT}"
 HUGO_EXIT_CODE=$?