feat: support npm workspaces for local development

Add workspaces configuration and workspace-aware scripts for developing
with a local frontend-base.  Decouple clean from build in the Makefile
so watch mode can rebuild without wiping dist/.

Part of openedx/frontend-base#184

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: arbrandes

.gitignore

@@ -3,6 +3,7 @@ npm-debug.log
 coverage
 module.config.js
 dist/
+packages/
 /*.tgz
 
 ### i18n ###

Makefile

@@ -32,7 +32,7 @@ requirements:  ## install ci requirements
 clean:
 	rm -rf dist
 
-build: clean
+build:
 	tsc --project tsconfig.build.json
 	find src -type f \( -name '*.scss' -o \( \( -name '*.png' -o -name '*.svg' \) -path '*/assets/*' \) \) -exec sh -c '\
 	  for f in "$$@"; do \

nodemon.json

@@ -0,0 +1,6 @@
+{
+  "watch": [
+    "src"
+  ],
+  "ext": "js,jsx,ts,tsx,scss,png,svg"
+}