Reload the browser on template and static changes in dev

Adds django-browser-reload: runserver already restarts on Python changes, but
the browser had to be refreshed by hand for every template or CSS edit. It also
watches static/, so a Tailwind rebuild now refreshes the page on its own.

Mounted only under DEBUG -- it injects a script into every HTML response and
serves an open event stream, neither of which belongs in production; a test
holds that line. Its endpoint is exempt from RequireMFAMiddleware, otherwise a
not-yet-enrolled staff user has the stream redirected away and live reload dies
on the MFA enrolment page, which is exactly a page we are restyling.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

uv.lock

@@ -213,6 +213,19 @@ mfa = [
     { name = "qrcode" },
 ]
 
+[[package]]
+name = "django-browser-reload"
+version = "1.21.0"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "asgiref" },
+    { name = "django" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/79/ef/ab407c1a2f14e13c75a6419a2d124954aa0364f62580ad95a3d31dc6c73d/django_browser_reload-1.21.0.tar.gz", hash = "sha256:3335ad3d107eb657f623d1a8e680dfbcab8a83ae1f94df1895e069dddf5604ba", size = 15800, upload-time = "2025-09-22T17:00:35.199Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/46/61/1b4a8c589652859995bcab87682286443eb9fdf2d7fd584975b9ffc1db33/django_browser_reload-1.21.0-py3-none-any.whl", hash = "sha256:0b2a86ab460774fa9bb142a121c70e75a72f18109f51a4f6de409cd633d3a70d", size = 12852, upload-time = "2025-09-22T17:00:33.479Z" },
+]
+
 [[package]]
 name = "django-lucide"
 version = "1.3.1"
@@ -379,6 +392,7 @@ dependencies = [
 [package.dev-dependencies]
 dev = [
     { name = "coverage" },
+    { name = "django-browser-reload" },
     { name = "ruff" },
 ]
 
@@ -398,6 +412,7 @@ requires-dist = [
 [package.metadata.requires-dev]
 dev = [
     { name = "coverage", specifier = ">=7.15.0" },
+    { name = "django-browser-reload", specifier = ">=1.21.0" },
     { name = "ruff", specifier = ">=0.15.17" },
 ]