feat(contact): implement Formspree contact form submission

- Enable contact form fields with component IDs
- Add callback for Formspree POST with JSON/AJAX
- Include honeypot spam protection (_gotcha field)
- Handle validation, loading, success/error states
- Clear form on successful submission
- Add lessons learned documentation

Closes #92, #93, #94

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

portfolio_app/pages/contact.py

@@ -2,6 +2,7 @@
 
 import dash
 import dash_mantine_components as dmc
+from dash import html
 from dash_iconify import DashIconify
 
 dash.register_page(__name__, path="/contact", name="Contact")
@@ -51,51 +52,57 @@ def create_intro_section() -> dmc.Stack:
 
 
 def create_contact_form() -> dmc.Paper:
-    """Create the contact form (disabled in Phase 1)."""
+    """Create the contact form with Formspree integration."""
     return dmc.Paper(
         dmc.Stack(
             [
                 dmc.Title("Send a Message", order=2, size="h4"),
-                dmc.Alert(
-                    "Contact form submission is coming soon. Please use the direct contact "
-                    "methods below for now.",
-                    title="Form Coming Soon",
-                    color="blue",
-                    variant="light",
-                ),
+                # Feedback container for success/error messages
+                html.Div(id="contact-feedback"),
                 dmc.TextInput(
+                    id="contact-name",
                     label="Name",
                     placeholder="Your name",
                     leftSection=DashIconify(icon="tabler:user", width=18),
-                    disabled=True,
+                    required=True,
                 ),
                 dmc.TextInput(
+                    id="contact-email",
                     label="Email",
                     placeholder="your.email@example.com",
                     leftSection=DashIconify(icon="tabler:mail", width=18),
-                    disabled=True,
+                    required=True,
                 ),
                 dmc.Select(
+                    id="contact-subject",
                     label="Subject",
                     placeholder="Select a subject",
                     data=SUBJECT_OPTIONS,
                     leftSection=DashIconify(icon="tabler:tag", width=18),
-                    disabled=True,
                 ),
                 dmc.Textarea(
+                    id="contact-message",
                     label="Message",
                     placeholder="Your message...",
                     minRows=4,
-                    disabled=True,
+                    required=True,
+                ),
+                # Honeypot field for spam protection (hidden from users)
+                dmc.TextInput(
+                    id="contact-gotcha",
+                    style={"position": "absolute", "left": "-9999px"},
+                    tabIndex=-1,
+                    autoComplete="off",
                 ),
                 dmc.Button(
                     "Send Message",
+                    id="contact-submit",
                     fullWidth=True,
                     leftSection=DashIconify(icon="tabler:send", width=18),
-                    disabled=True,
                 ),
             ],
             gap="md",
+            style={"position": "relative"},
         ),
         p="xl",
         radius="md",