feat: add dev-ui make target for live JS reloading

Add LRC_STATIC_DEV_DIR env var support to the staticserve package.
When set, all three serving paths (GetStaticHandler, ReadFile,
RenderPreactHTML) read from the filesystem instead of the embedded FS.

Add dev-ui Makefile target that sets LRC_STATIC_DEV_DIR to the static
source directory and runs the fake review with a 5s wait. Editing any
JS file in internal/staticserve/static/ is visible on browser refresh
without rebuilding the binary.

Author: lovestaco

Makefile

@@ -1,4 +1,4 @@
-.PHONY: build build-win build-all build-local build-local-test run run-fake-review bump release release-internal release-gh clean test testall test-pkg upload-secrets download-secrets security-govulncheck security-govulncheck-json security-osv security-triage security-gitleaks security-b2-audit security-b2-cleanup-plan security-b2-cleanup-apply security-publish-release-manifest security-secret-regression security-sbom security-sbom-cyclonedx security-sbom-spdx security-sbom-validate release-notes-init release-notes-check release-preflight
+.PHONY: build build-win build-all build-local build-local-test run run-fake-review dev-ui bump release release-internal release-gh clean test testall test-pkg upload-secrets download-secrets security-govulncheck security-govulncheck-json security-osv security-triage security-gitleaks security-b2-audit security-b2-cleanup-plan security-b2-cleanup-apply security-publish-release-manifest security-secret-regression security-sbom security-sbom-cyclonedx security-sbom-spdx security-sbom-validate release-notes-init release-notes-check release-preflight
 
 # Go parameters
 GOENV=env -u GOROOT
@@ -70,6 +70,14 @@ run: build-local
 run-fake-review: build-local-test
 	@WAIT=$${WAIT:-30s} TMP_REPO=$${TMP_REPO:-/tmp/lrc-fake-review-repo} scripts/fake_review.sh $(ARGS)
 
+# Run fake review with live JS reloading — edit files in internal/staticserve/static/, refresh browser
+# No rebuild needed after JS changes: just edit and refresh the browser tab.
+dev-ui: build-local-test
+	@LRC_STATIC_DEV_DIR=$(CURDIR)/internal/staticserve/static \
+	 WAIT=$${WAIT:-5s} \
+	 TMP_REPO=$${TMP_REPO:-/tmp/lrc-fake-review-repo} \
+	 scripts/fake_review.sh $(ARGS)
+
 # Bump lrc version by editing appVersion in main.go
 # Prompts for version bump type (patch/minor/major)
 bump:

internal/staticserve/static_serve.go

@@ -2,7 +2,12 @@ package staticserve
 
 import (
 	"embed"
+	"encoding/json"
+	"mime"
 	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
 
 	"github.com/HexmosTech/git-lrc/result"
 )
@@ -16,13 +21,38 @@ type JSONHunkData = result.JSONHunkData
 type JSONLineData = result.JSONLineData
 type JSONCommentData = result.JSONCommentData
 
+func devStaticDir() string {
+	return os.Getenv("LRC_STATIC_DEV_DIR")
+}
+
 // RenderPreactHTML renders the Preact-based HTML with embedded JSON data.
 func RenderPreactHTML(data *result.HTMLTemplateData) (string, error) {
+	if dir := devStaticDir(); dir != "" {
+		jsonData := result.ConvertToJSONData(data)
+		jsonBytes, err := json.Marshal(jsonData)
+		if err != nil {
+			return "", err
+		}
+		htmlBytes, err := os.ReadFile(filepath.Join(dir, "index.html"))
+		if err != nil {
+			return "", err
+		}
+		html := strings.Replace(string(htmlBytes), "{{.JSONData}}", string(jsonBytes), 1)
+		if data.FriendlyName != "" {
+			html = strings.Replace(html, "<title>LiveReview Results</title>",
+				"<title>LiveReview Results — "+data.FriendlyName+"</title>", 1)
+		}
+		return html, nil
+	}
 	return result.RenderPreactHTML(data, staticFiles)
 }
 
 // GetStaticHandler returns an HTTP handler for serving static files.
 func GetStaticHandler() http.Handler {
+	if dir := devStaticDir(); dir != "" {
+		_ = mime.AddExtensionType(".mjs", "application/javascript; charset=utf-8")
+		return http.FileServer(http.Dir(dir))
+	}
 	return result.GetStaticHandler(staticFiles)
 }
 
@@ -31,7 +61,10 @@ func ServeStaticFile(w http.ResponseWriter, r *http.Request, filename string) er
 	return result.ServeStaticFile(w, filename, staticFiles)
 }
 
-// ReadFile reads a file from the embedded static directory.
+// ReadFile reads a file from the embedded static directory (or filesystem in dev mode).
 func ReadFile(name string) ([]byte, error) {
+	if dir := devStaticDir(); dir != "" {
+		return os.ReadFile(filepath.Join(dir, name))
+	}
 	return staticFiles.ReadFile("static/" + name)
 }