Phase 0 Complete: Tasks 0.7-0.20

- 0.7: UI-Design-Richtlinien (docs/ui-design-guidelines.md, 535 lines)
- 0.8: Theme-Customization Backend (4 theme fields, migration 0023)
- 0.9: Theme-Customization Frontend (SettingsTheme.tsx, themeStore.ts, live preview)
- 0.10: RBAC-Audit (4 plugins secured, 53 routes with require_permission)
- 0.11: LiteLLM-Cleanup (llm_client.py migrated from httpx to litellm)
- 0.12: KI-Agent-Framework docs (plugin-development-guide.md, agent_capabilities field)
- 0.13: Heartbeat configurable (ProactiveSettings, migration 0024, frontend UI)
- 0.14: Unified Search Field-Level RBAC (resolve_permissions + filter_fields_by_permission)
- 0.15: Undo/History-System (EntityHistory model, service, routes, migration 0025, HistoryViewer)
- 0.16: Storage Backend (LocalStorage + S3Storage, DMS/attachments/mail updated)
- 0.17: Import/Export unified Contact fields (firstname, surname, email_1, phone_1)
- 0.18: .gitignore & Config-Cleanup (webui→frontend, python-jose removed, .env untracked)
- 0.19: Mail-Salt Security-Fix (per-account random salt, migration 0026)
- 0.20: AGPL replaced (PyMuPDF→pypdf, OnlyOffice→Collabora, LICENSE + THIRD_PARTY_LICENSES.md)

app/plugins/builtins/unified_search/text_extraction.py

@@ -14,7 +14,7 @@ async def extract_text_from_file(file_path: str, mime_type: str) -> str:
     """Extract text content from a file based on its MIME type.
 
     Supports:
-    - PDF (via PyMuPDF/fitz)
+    - PDF (via pypdf)
     - DOCX (via python-docx)
     - XLSX (via openpyxl)
     - PPTX (via python-pptx)
@@ -57,14 +57,15 @@ def _truncate(text: str) -> str:
 
 
 async def _extract_pdf(file_path: str) -> str:
-    """Extract text from PDF using PyMuPDF (fitz)."""
-    import fitz  # PyMuPDF
+    """Extract text from PDF using pypdf (BSD-licensed)."""
+    from pypdf import PdfReader
 
-    doc = fitz.open(file_path)
+    reader = PdfReader(file_path)
     parts: list[str] = []
-    for page in doc:
-        parts.append(page.get_text())
-    doc.close()
+    for page in reader.pages:
+        text = page.extract_text()
+        if text:
+            parts.append(text)
     return _truncate("\n".join(parts))