refactor(views): split file views into summary, detail, process, and annotations pages

- /files/<id> → new summary page with navigation cards
- /files/<id>/detail → document detail with metadata, preview, text
- /files/<id>/process → processing pipeline status and history
- /files/<id>/annotations → comments & annotations with EmbedPDF viewer
- /files/<id>/comments → redirects to /annotations
- Added embed-pdf-viewer as git submodule for PDF annotation viewer
- Updated all navigation links across templates
- Updated all tests to use new URL structure

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>
Agent-Logs-Url: https://github.com/christianlouis/DocuElevate/sessions/12276514-bd3d-4e3e-84d9-5977d1f82b19

tests/test_file_detail_enhancements.py

@@ -50,7 +50,7 @@ def test_file_detail_page_with_metadata(client: TestClient, db_session, sample_p
     db_session.refresh(file_record)
 
     # Get detail page
-    response = client.get(f"/files/{file_record.id}/detail")
+    response = client.get(f"/files/{file_record.id}/process")
     assert response.status_code == 200
 
     html = response.text
@@ -85,7 +85,7 @@ def test_file_detail_with_gpt_metadata(client: TestClient, db_session, sample_pd
     db_session.refresh(file_record)
 
     # Get detail page
-    response = client.get(f"/files/{file_record.id}/detail")
+    response = client.get(f"/files/{file_record.id}/process")
     assert response.status_code == 200
 
     html = response.text
@@ -190,7 +190,7 @@ def test_file_detail_shows_file_status_indicators(client: TestClient, db_session
     db_session.commit()
     db_session.refresh(file_record)
 
-    response = client.get(f"/files/{file_record.id}/detail")
+    response = client.get(f"/files/{file_record.id}/process")
     assert response.status_code == 200
 
     html = response.text