Make old project runnable on Go 1.27 with mise and READMEHEADmaster

- init go.mod (Go 1.27, progressbar/v3 v3.19.1) and fix import
- fix FMin returning max, remove deprecated RenderBlank, apply go fix range loops
- add mise.toml (go 1.27, tasks: build/run/check with go fix -diff/clean)
- add focused README and update .gitignore for build artifacts

1 files changed, 23 insertions, 0 deletions

diff --git a/mise.toml b/mise.toml
new file mode 100644
index 0000000..bfa3c33
--- /dev/null
+++ b/mise.toml
@@ -0,0 +1,23 @@
+[tools]
+go = "1.27"
+
+[tasks.build]
+description = "Build the ray tracer binary"
+run = "go build -o goraytracer ."
+
+[tasks.run]
+description = "Render the default scene to img.png (2000x1000, ~5s)"
+run = "go run ."
+
+[tasks.check]
+description = "Format, vet, apply go fix, and build"
+run = [
+  "go fmt ./...",
+  "go fix -diff ./...",
+  "go vet ./...",
+  "go build ./...",
+]
+
+[tasks.clean]
+description = "Remove rendered image and binary"
+run = "rm -f img.png goraytracer"