feat: Add uv Docker, Postgres, and company linking

Introduces uv-based Docker workflow with non-root runtime, cached installs, and uv-run for web and Celery. Updates docker-compose to Postgres + Redis, loads .env, and removes source bind mount for reproducible builds.

Switches settings to use Postgres when env is present with SQLite fallback; broadens allowed hosts for containerized development. Adds psycopg2-binary and updates sample env for Redis in Docker.

Adds company scoping to external data models and links sessions during ingestion; provides management commands to seed a Jumbo company/users and sync external chat data into the dashboard.

Includes .dockerignore, TypeScript config and typings, and minor template/docs tweaks.

Requires database migration.

dashboard_project/data_integration/migrations/0003_chatsession_company_externaldatasource_company.py

@@ -0,0 +1,38 @@
+# Generated by Django 5.2.7 on 2025-11-05 18:20
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("accounts", "0001_initial"),
+        ("data_integration", "0002_externaldatasource_error_count_and_more"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="chatsession",
+            name="company",
+            field=models.ForeignKey(
+                blank=True,
+                help_text="Company this session belongs to",
+                null=True,
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="external_chat_sessions",
+                to="accounts.company",
+            ),
+        ),
+        migrations.AddField(
+            model_name="externaldatasource",
+            name="company",
+            field=models.ForeignKey(
+                blank=True,
+                help_text="Company this data source belongs to",
+                null=True,
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="external_data_sources",
+                to="accounts.company",
+            ),
+        ),
+    ]