Refactor documentation and diagrams for web/pipeline. (#272)

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com> for assistance with diagram creation and documentation prose updates.

docs/makefile

@@ -0,0 +1,43 @@
+# Makefile for rendering all Mermaid (.mmd) diagrams to SVG,
+# preserving the source directory structure under OUT_ROOT.
+#
+# Usage:
+#   make            # render all diagrams
+#   make clean      # remove all rendered output
+#   make FORMAT=png # render as PNG instead of SVG
+#   make FORMAT=pdf # render as PDF instead of SVG
+#
+# Requires: @mermaid-js/mermaid-cli (mmdc) on PATH
+#   npm install -g @mermaid-js/mermaid-cli
+
+SRC_ROOT  := .
+OUT_ROOT  := rendered-diagrams
+FORMAT    := svg
+
+# Optional: point to a shared Mermaid config/theme file if you have one.
+# CONFIG    := ./mermaidconfig.json
+# CONFIG_FLAG := -c $(CONFIG)
+CONFIG_FLAG :=
+
+# Find every .mmd file under SRC_ROOT, excluding the output directory itself.
+SRC_FILES := $(shell find $(SRC_ROOT) -type f -name "*.mmd" -not -path "./$(OUT_ROOT)/*")
+
+# Map each source file to its corresponding output file, preserving subdirectories.
+OUT_FILES := $(patsubst $(SRC_ROOT)/%.mmd,$(OUT_ROOT)/%.$(FORMAT),$(SRC_FILES))
+
+.PHONY: all clean list
+
+all: $(OUT_FILES)
+
+# Pattern rule: build any output file from its matching .mmd source file,
+# creating the destination subdirectory as needed.
+$(OUT_ROOT)/%.$(FORMAT): $(SRC_ROOT)/%.mmd
+	@mkdir -p $(dir $@)
+	mmdc $(CONFIG_FLAG) -i $< -o $@
+
+clean:
+	rm -rf $(OUT_ROOT)
+
+# Debug helper: print which source files were discovered.
+list:
+	@echo "$(SRC_FILES)" | tr ' ' '\n'