fix: restore all code deleted/truncated by d2217531 Jules SSRF commit

Commit d2217531 (google-labs-jules SSRF fix) catastrophically deleted
11,500+ lines across 100+ files while fixing an unrelated IMAP issue.

Restored from d2217531^ (pre-bad-commit state):

Deleted files (fully restored):
- app/api/{automation,classification_rules,comments,sharing}.py
- app/middleware/upload_rate_limit.py
- app/tasks/{automation_tasks,classify_document}.py
- app/utils/{automation_hooks,classification_rules}.py
- docs/AppleAppStoreCompliance.md
- frontend/input.css, package.json, package-lock.json, tailwind.config.js
- frontend/static/js/{annotations,claim,comments,sharing}.js
- frontend/templates/{admin_connections,file_annotations,file_summary}.html
- tests/{test_api_files_comprehensive,test_auth_extended,test_sharing,
         test_comments,test_connections,test_imap_profiles,test_api_sessions,
         test_automation,test_classification_rules,test_api_advanced_filters,
         test_api_classification_rules,test_upload_rate_limit,test_api_dropbox,
         test_classify_document,test_comments_ui,test_upload_to_icloud,
         test_api_onedrive_comprehensive,test_frontend_build,test_sentry,
         test_diagnostic,test_database,test_views_dropbox,test_local_auth}.py

Truncated files (content restored):
- app/{auth,config,main,models,celery_worker,database}.py
- app/api/{__init__,api_tokens,diagnostic,dropbox,files,google_drive,
           integrations,local_auth,mobile,onedrive,pipelines,qr_auth,
           settings,url_upload}.py
- app/middleware/upload_rate_limit.py
- app/tasks/upload_to_nextcloud.py
- app/utils/{allowed_types,settings_service,settings_sync,user_scope,webhook}.py
- app/views/{base,dropbox,files,google_drive,onedrive,settings}.py
- docs/{API,AuthenticationSetup,ConfigurationGuide,DatabaseConfiguration,
        DeploymentGuide,DropboxSetup,GoogleDriveSetup,KubernetesDeployment,
        MobileApp,OneDriveSetup,ProductionReadiness,SentrySetup,
        SocialLoginSetup,UserGuide}.md
- frontend/static/{js/upload.js,styles.css}
- frontend/templates/{api_tokens,base,devices,dropbox,dropbox_callback,
                      file_view,files,google_drive,onedrive,onedrive_callback,
                      signup}.html
- frontend/translations/en.json
- migrations/env.py
- tests/{conftest,test_api_integrations,test_api_mobile,test_api_settings,
         test_api_tokens,test_audit_logs,test_duplicates,test_imap_tasks,
         test_setup_wizard,test_views_files_comprehensive}.py

Security fixes kept from post-d2217531 commits:
- app/utils/network.py: DNS SSRF fail-secure fix (06b0fced)
- app/utils/file_operations.py: path traversal fix (1018ea17)
- tests/test_imap_tasks.py: re-applied 4 is_private_ip mock patches

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>
Agent-Logs-Url: https://github.com/christianlouis/DocuElevate/sessions/51133dd8-9bec-41ab-aa10-3de753634187

docs/UserGuide.md

@@ -87,7 +87,7 @@ DocuElevate provides multiple convenient ways to upload documents to the system.
 
 #### Supported File Types
 - **Documents**: PDF, Word (.doc, .docx), Excel (.xls, .xlsx), PowerPoint (.ppt, .pptx)
-- **Images**: JPEG, PNG, GIF, BMP, TIFF, WebP, SVG
+- **Images**: JPEG, PNG, GIF, BMP, TIFF, WebP, SVG, HEIC, HEIF
 - **Text**: Plain text (.txt), CSV, RTF, HTML, XML, Markdown
 - **Maximum file size**: 500MB per file
 
@@ -582,7 +582,25 @@ Processing pipelines let you define exactly what happens to your documents when
 | `embed_metadata` | Write extracted metadata into the PDF document properties |
 | `compute_embedding` | Compute semantic embeddings for similarity search |
 | `send_to_destinations` | Upload the processed document to all configured storage destinations |
-| `classify` | Classify the document type with AI |
+| `classify` | Classify the document type using rules (filename patterns, content keywords, metadata) |
+
+#### Classify step – rule-based document classification
+
+The `classify` step assigns a category to each document by evaluating **built-in** and **custom** classification rules.  Rules are matched against three signals:
+
+- **Filename patterns** — regex matched against the original filename (e.g. `(?i)invoice` matches filenames containing "invoice").
+- **Content keywords** — pipe-separated keywords matched against the OCR text (e.g. `invoice number|amount due`).
+- **Metadata match** — `field=value` matched against existing AI metadata (e.g. `document_type=Invoice`).
+
+**Pre-built categories** include: Invoice, Contract, Receipt, Letter, Report, Bank Statement, Tax Document, Insurance, and Payslip.  You can also define your own custom categories.
+
+The classification result is stored in the document's `ai_metadata` under the `classification` key with the matched category, confidence score, and list of matched rules.  If no `document_type` was previously set by AI metadata extraction, the classify step will also populate it.
+
+> **Tip:** Manage custom classification rules via **Settings → Classification Rules** or the `/api/classification-rules/` API.  See the [API Documentation](./API.md#classification-rules) for details.
+
+| Option | Type | Default | Description |
+|--------|------|---------|-------------|
+| `use_builtin_rules` | boolean | `true` | Include the pre-built classification rules |
 
 #### OCR step options
 
@@ -687,6 +705,64 @@ You can test your rules without actually routing a document using the
 **evaluate** endpoint (`POST /api/routing-rules/evaluate`).  For the full
 API reference, see [API Documentation](API.md#routing-rules).
 
+## Comments & Annotations
+
+The file detail page includes a **collaboration panel** for threaded
+comments and PDF annotations, allowing team members to discuss documents
+directly within DocuElevate.
+
+### Comments
+
+The **Comments** panel is on the left side of the collaboration section at
+the bottom of the file detail page.
+
+#### Viewing Comments
+Open any file's detail page (`/files/{id}/detail`). Existing comments load
+automatically, displayed in a threaded tree — replies are nested under their
+parent.
+
+#### Adding a Comment
+1. Type your comment in the text area at the bottom of the Comments panel.
+2. Use `@username` to mention another user — an autocomplete dropdown
+   appears as you type after the `@` symbol. Use arrow keys and Enter to
+   select a user.
+3. Click **Add comment** to post.
+
+#### Replying to a Comment
+Click the **Reply** button on any top-level comment. A reply text area
+appears inline; type your response and click **Reply** to post.
+
+#### Editing & Deleting
+You can edit or delete your own comments using the **Edit** and trash
+buttons. Edits re-extract @mentions automatically.
+
+#### Resolving Threads
+Click **Resolve** on a top-level comment to mark the thread as resolved
+(shown with a green badge). Click **Reopen** to re-open it.
+
+### Annotations
+
+The **Annotations** panel is on the right side of the collaboration
+section.
+
+#### Adding an Annotation
+1. Type the annotation content in the text area.
+2. Set the **Page** number the annotation refers to.
+3. Choose a **Type**: Note, Highlight, Underline, or Strikethrough.
+4. Pick a **Color** using the color picker.
+5. Click **Add annotation** to save.
+
+#### Editing & Deleting
+You can edit or delete your own annotations using the pencil and trash
+buttons. When editing, you can also change the annotation type.
+
+### @Mention Autocomplete
+
+When typing `@` followed by characters in the comment input, an
+autocomplete dropdown shows matching users (sourced from the
+`/api/users/mentionable` endpoint). Navigate with arrow keys and press
+Enter or click to insert the mention.
+
 ## API Access
 
 For programmatic access, DocuElevate provides a comprehensive REST API: