feat: OAuth user fixes + dashboard UI improvements (v3.2.0)

- Bug A: Fix OAuth consent redirect loop (return_url path-relative)
- Bug B: Accept OAuth JWT tokens on /u/{user_id}/{alias}/mcp
- Bug C: Add user OAuth client CRUD (list/create/delete) + new page
- D-1: Sidebar border via Tailwind class, version footer in sidebar
- D-2: Remove broken setInterval targeting #stats-container
- D-3: 404.html purple primary colors + system dark mode support
- D-4: Fix invisible buttons (bg-gray-200 + text-white in light mode)
- D-5: Pin Alpine.js to 3.14.8, remove duplicate CSRF meta tag
- D-6: Fix invisible lang toggle button in settings (dark mode)

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

server.py

@@ -126,7 +126,7 @@ logging.basicConfig(
 logger = logging.getLogger(__name__)
 
 # Server version — read from pyproject.toml, fallback to importlib.metadata
-SERVER_VERSION = "3.2.0"
+SERVER_VERSION = "3.1.0"
 try:
     _pyproject = os.path.join(os.path.dirname(__file__), "pyproject.toml")
     with open(_pyproject) as _f:
@@ -2464,7 +2464,8 @@ async def oauth_authorize(request: Request):
                 "lang": lang,  # Language code (en/fa)
                 "t": translations,  # All translations for this language
                 "session_user": session_user,
-                "return_url": str(request.url),
+                "return_url": str(request.url.path)
+                + (("?" + str(request.url.query)) if request.url.query else ""),
             },
         )