feat: Email templates, bulk delete, communication credits, plan features

- Add email template presets for Browse Templates tab (12 templates)
- Add bulk selection and deletion for My Templates tab
- Add communication credits system with Twilio integration
- Add payment views for credit purchases and auto-reload
- Add SMS reminder and masked calling plan permissions
- Fix appointment status mapping (frontend/backend mismatch)
- Clear masquerade stack on login/logout for session hygiene
- Update platform settings with credit configuration
- Add new migrations for Twilio and Stripe payment fields

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.idea/smoothschedule2.iml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module version="4">
+  <component name="PyDocumentationSettings">
+    <option name="format" value="PLAIN" />
+    <option name="myDocStringFormat" value="Plain" />
+  </component>
+  <component name="TemplatesService">
+    <option name="TEMPLATE_CONFIGURATION" value="Jinja2" />
+    <option name="TEMPLATE_FOLDERS">
+      <list>
+        <option value="$MODULE_DIR$/smoothschedule/schedule/templates" />
+      </list>
+    </option>
+  </component>
+  <component name="TestRunnerService">
+    <option name="PROJECT_TEST_RUNNER" value="py.test" />
+  </component>
+</module>