feat: support manual add and edit for memory facts (#1538)

* feat: support manual add and edit for memory facts

* fix: restore memory updater save helper

* fix: address memory fact review feedback

* fix: remove duplicate memory fact edit action

* docs: simplify memory fact review setup

* docs: relax memory review startup instructions

* fix: clear rebase marker in memory settings page

* fix: address memory fact review and format issues

* fix: address memory fact review feedback

* refactor: make memory fact updates explicit patch semantics

---------

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

backend/app/gateway/routers/memory.py

@@ -5,9 +5,11 @@ from pydantic import BaseModel, Field
 
 from deerflow.agents.memory.updater import (
     clear_memory_data,
+    create_memory_fact,
     delete_memory_fact,
     get_memory_data,
     reload_memory_data,
+    update_memory_fact,
 )
 from deerflow.config.memory_config import get_memory_config
 
@@ -58,6 +60,31 @@ class MemoryResponse(BaseModel):
     facts: list[Fact] = Field(default_factory=list)
 
 
+def _map_memory_fact_value_error(exc: ValueError) -> HTTPException:
+    """Convert updater validation errors into stable API responses."""
+    if exc.args and exc.args[0] == "confidence":
+        detail = "Invalid confidence value; must be between 0 and 1."
+    else:
+        detail = "Memory fact content cannot be empty."
+    return HTTPException(status_code=400, detail=detail)
+
+
+class FactCreateRequest(BaseModel):
+    """Request model for creating a memory fact."""
+
+    content: str = Field(..., min_length=1, description="Fact content")
+    category: str = Field(default="context", description="Fact category")
+    confidence: float = Field(default=0.5, ge=0.0, le=1.0, description="Confidence score (0-1)")
+
+
+class FactPatchRequest(BaseModel):
+    """PATCH request model that preserves existing values for omitted fields."""
+
+    content: str | None = Field(default=None, min_length=1, description="Fact content")
+    category: str | None = Field(default=None, description="Fact category")
+    confidence: float | None = Field(default=None, ge=0.0, le=1.0, description="Confidence score (0-1)")
+
+
 class MemoryConfigResponse(BaseModel):
     """Response model for memory configuration."""
 
@@ -156,6 +183,28 @@ async def clear_memory() -> MemoryResponse:
     return MemoryResponse(**memory_data)
 
 
+@router.post(
+    "/memory/facts",
+    response_model=MemoryResponse,
+    summary="Create Memory Fact",
+    description="Create a single saved memory fact manually.",
+)
+async def create_memory_fact_endpoint(request: FactCreateRequest) -> MemoryResponse:
+    """Create a single fact manually."""
+    try:
+        memory_data = create_memory_fact(
+            content=request.content,
+            category=request.category,
+            confidence=request.confidence,
+        )
+    except ValueError as exc:
+        raise _map_memory_fact_value_error(exc) from exc
+    except OSError as exc:
+        raise HTTPException(status_code=500, detail="Failed to create memory fact.") from exc
+
+    return MemoryResponse(**memory_data)
+
+
 @router.delete(
     "/memory/facts/{fact_id}",
     response_model=MemoryResponse,
@@ -174,6 +223,31 @@ async def delete_memory_fact_endpoint(fact_id: str) -> MemoryResponse:
     return MemoryResponse(**memory_data)
 
 
+@router.patch(
+    "/memory/facts/{fact_id}",
+    response_model=MemoryResponse,
+    summary="Patch Memory Fact",
+    description="Partially update a single saved memory fact by its fact id while preserving omitted fields.",
+)
+async def update_memory_fact_endpoint(fact_id: str, request: FactPatchRequest) -> MemoryResponse:
+    """Partially update a single fact manually."""
+    try:
+        memory_data = update_memory_fact(
+            fact_id=fact_id,
+            content=request.content,
+            category=request.category,
+            confidence=request.confidence,
+        )
+    except ValueError as exc:
+        raise _map_memory_fact_value_error(exc) from exc
+    except KeyError as exc:
+        raise HTTPException(status_code=404, detail=f"Memory fact '{fact_id}' not found.") from exc
+    except OSError as exc:
+        raise HTTPException(status_code=500, detail="Failed to update memory fact.") from exc
+
+    return MemoryResponse(**memory_data)
+
+
 @router.get(
     "/memory/config",
     response_model=MemoryConfigResponse,