fix: add missing migration and encryptid.browser.js placeholder

- Add migration 0003 for visibility and owner_did fields on SharedSpace
  (fields were in model but migration was never created, causing 500s)
- Add placeholder encryptid.browser.js to fix staticfiles manifest error

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

files/migrations/0003_sharedspace_owner_did_sharedspace_visibility.py

@@ -0,0 +1,23 @@
+# Generated by Django 5.2.8 on 2026-02-15 22:13
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('files', '0002_alter_sharedspace_max_file_size_mb'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='sharedspace',
+            name='owner_did',
+            field=models.CharField(blank=True, default='', help_text='EncryptID DID of the space owner', max_length=255),
+        ),
+        migrations.AddField(
+            model_name='sharedspace',
+            name='visibility',
+            field=models.CharField(choices=[('public', 'Public'), ('public_read', 'Public Read'), ('authenticated', 'Authenticated'), ('members_only', 'Members Only')], default='public_read', help_text='Who can access this space', max_length=20),
+        ),
+    ]

portal/static/portal/encryptid.browser.js

@@ -0,0 +1,3 @@
+/* EncryptID Browser SDK - placeholder
+ * TODO: Replace with actual SDK from https://encryptid.jeffemmett.com
+ */