Phase 4: Documents & Memory — upload, FTS, AI tools, context injection

Backend:
- Document + MemoryEntry models with Alembic migration (GIN FTS index)
- File upload endpoint with path traversal protection (sanitized filenames)
- Background document text extraction (PyMuPDF)
- Full-text search on extracted_text via PostgreSQL tsvector/tsquery
- Memory CRUD with enum-validated categories/importance, field allow-list
- AI tools: save_memory, search_documents, get_memory (Claude function calling)
- Tool execution loop in stream_ai_response (multi-turn tool use)
- Context assembly: injects critical memory + relevant doc excerpts
- File storage abstraction (local filesystem, S3-swappable)
- Secure file deletion (DB flush before disk delete)

Frontend:
- Document upload dialog (drag-and-drop + file picker)
- Document list with status badges, search, download (via authenticated blob)
- Document viewer with extracted text preview
- Memory list grouped by category with importance color coding
- Memory editor with category/importance dropdowns
- Documents + Memory pages with full CRUD
- Enabled sidebar navigation for both sections

Review fixes applied:
- Sanitized upload filenames (path traversal prevention)
- Download via axios blob (not bare <a href>, preserves auth)
- Route ordering: /search before /{id}/reindex
- Memory update allows is_active=False + field allow-list
- MemoryEditor form resets on mode switch
- Literal enum validation on category/importance schemas
- DB flush before file deletion for data integrity

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/schemas/memory.py

@@ -0,0 +1,43 @@
+import uuid
+from datetime import datetime
+from typing import Literal
+
+from pydantic import BaseModel, Field
+
+CategoryType = Literal["condition", "medication", "allergy", "vital", "document_summary", "other"]
+ImportanceType = Literal["critical", "high", "medium", "low"]
+
+
+class CreateMemoryRequest(BaseModel):
+    category: CategoryType
+    title: str = Field(min_length=1, max_length=255)
+    content: str = Field(min_length=1)
+    source_document_id: uuid.UUID | None = None
+    importance: ImportanceType = "medium"
+    is_active: bool = True
+
+
+class UpdateMemoryRequest(BaseModel):
+    category: CategoryType | None = None
+    title: str | None = None
+    content: str | None = None
+    importance: ImportanceType | None = None
+    is_active: bool | None = None
+
+
+class MemoryEntryResponse(BaseModel):
+    id: uuid.UUID
+    user_id: uuid.UUID
+    category: str
+    title: str
+    content: str
+    source_document_id: uuid.UUID | None
+    importance: str
+    is_active: bool
+    created_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class MemoryEntryListResponse(BaseModel):
+    entries: list[MemoryEntryResponse]