feat: implement bio landing page with dash-mantine-components

- Full bio page with hero, summary, tech stack, projects, social links
- MantineProvider theme integration in app.py
- Responsive layout using DMC SimpleGrid
- Added dash-iconify for social link icons
- Updated mypy overrides for DMC/iconify modules

Closes #11

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

portfolio_app/app.py

@@ -1,26 +1,28 @@
 """Dash application factory with Pages routing."""
 
 import dash
-from dash import html
+import dash_mantine_components as dmc
 
 from .config import get_settings
 
 
 def create_app() -> dash.Dash:
     """Create and configure the Dash application."""
-    settings = get_settings()
-
     app = dash.Dash(
         __name__,
         use_pages=True,
         suppress_callback_exceptions=True,
         title="Analytics Portfolio",
+        external_stylesheets=dmc.styles.ALL,
     )
 
-    app.layout = html.Div(
-        [
-            dash.page_container,
-        ]
+    app.layout = dmc.MantineProvider(
+        dash.page_container,
+        theme={
+            "primaryColor": "blue",
+            "fontFamily": "'Inter', sans-serif",
+        },
+        forceColorScheme="light",
     )
 
     return app