fix: merge main branch and renumber migration 037→040

Resolve all merge conflicts between our automation feature branch and
current main (v0.163.0, 920 commits ahead).

Conflicts resolved:
- app/api/__init__.py: add automation_router alongside main's new routers
  (classification_rules, qr_auth, sessions, system_reset)
- app/config.py: add main's new settings (dropbox_use_global_credentials,
  factory_reset_on_startup, enable_factory_reset)
- app/models.py: add main's new models (ClassificationRuleModel, UserSession,
  QRLoginChallenge, SharePoint integration type)
- app/utils/settings_service.py: merge automation_hooks_enabled with main's
  new metadata entries
- docs/API.md: merge automation API docs with main's classification rules docs
- docs/ConfigurationGuide.md: add factory reset settings
- tests/conftest.py: import both AutomationHook and new main models

Migration renumbered:
- 037_add_automation_hooks → 040_add_automation_hooks
- down_revision: 039_add_classification_rules (was 036_add_document_translation_fields)
- Chain: 036 → 037 → 038 → 039 → 040 (automation hooks)

For all non-automation files with conflicts, main's version was taken since
our branch did not modify those files (conflicts were from a stale prior merge).

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>
Agent-Logs-Url: https://github.com/christianlouis/DocuElevate/sessions/cb62f012-3b69-4415-835e-3857ce3e9f45

frontend/templates/signup.html

@@ -32,6 +32,14 @@
                 error: '',
                 async submit() {
                     this.error = '';
+                    if (this.username.length < 3 || this.username.length > 64) {
+                        this.error = 'Username must be between 3 and 64 characters.';
+                        return;
+                    }
+                    if (!/^[a-zA-Z0-9_-]+$/.test(this.username)) {
+                        this.error = 'Username may only contain letters, numbers, hyphens, and underscores. Dots and other special characters are not allowed.';
+                        return;
+                    }
                     if (this.password !== this.password_confirm) {
                         this.error = 'Passwords do not match.';
                         return;
@@ -58,7 +66,12 @@
                             }
                         } else {
                             const data = await resp.json();
-                            this.error = data.detail || 'Registration failed. Please try again.';
+                            const detail = data.detail;
+                            if (Array.isArray(detail)) {
+                                this.error = detail.map(e => e.msg || String(e)).join(' ') || 'Registration failed. Please try again.';
+                            } else {
+                                this.error = detail || 'Registration failed. Please try again.';
+                            }
                         }
                     } catch(e) {
                         this.error = 'Network error. Please try again.';