docs: 更新 examples/Readme.md 并新增 Readme.html

- 覆盖全部 10 个案例（原 Readme 只到 case06）
- 新增案例选择指南表格
- Readme.html 为深色主题独立 HTML 页面
  （含卡片布局、标签分类、代码高亮、响应式设计）
- 各案例详情对齐最新配置参数

engines/fortran/Makefile

@@ -0,0 +1,47 @@
+# engines/fortran/Makefile
+
+FC      = gfortran
+FFLAGS  = -O3 -march=native -Wall -Wextra
+SRCS    = main.f90
+LIB_SRC = dynamics_lib.f90
+
+UNAME_S := $(shell uname -s 2>/dev/null || echo Windows)
+
+ifeq ($(UNAME_S),Windows)
+  STATIC_FLAGS = -static-libgcc -static-libgfortran -static-libquadmath
+else
+  STATIC_FLAGS =
+endif
+
+TARGET = build/dynamics_f90.exe
+
+ifeq ($(UNAME_S),Linux)
+  DLL_TARGET = build/dynamics_f90.so
+  DLL_FLAGS  = -shared -fPIC
+else ifeq ($(UNAME_S),Darwin)
+  DLL_TARGET = build/dynamics_f90.dylib
+  DLL_FLAGS  = -dynamiclib
+else
+  DLL_TARGET = build/dynamics_f90.dll
+  DLL_FLAGS  = -shared -fPIC
+endif
+
+.PHONY: all dll clean
+
+all: $(TARGET)
+
+dll: $(DLL_TARGET)
+
+$(TARGET): $(SRCS) | build
+	$(FC) $(FFLAGS) $(STATIC_FLAGS) -o $@ $(SRCS)
+	@echo "  === Fortran engine built: $@ ==="
+
+$(DLL_TARGET): $(LIB_SRC) | build
+	$(FC) $(FFLAGS) $(STATIC_FLAGS) $(DLL_FLAGS) -o $@ $(LIB_SRC)
+	@echo "  === Fortran DLL built: $@ ==="
+
+build:
+	mkdir -p build
+
+clean:
+	rm -rf build *.o *.mod