Add REPL effect detection and input handling to pipeline runner

- Detect REPL effect in pipeline and enable interactive mode
- Enable raw terminal mode for REPL input capture
- Add keyboard input loop for REPL commands (return, up/down arrows, backspace)
- Process commands and handle pipeline mutations from REPL
- Fix lint issues in graph and REPL modules (type annotations, imports)

engine/pipeline/graph.py

@@ -22,8 +22,8 @@ Usage:
 """
 
 from dataclasses import dataclass, field
-from typing import Any, Dict, List, Optional, Union
 from enum import Enum
+from typing import Any
 
 
 class NodeType(Enum):
@@ -45,7 +45,7 @@ class Node:
 
     name: str
     type: NodeType
-    config: Dict[str, Any] = field(default_factory=dict)
+    config: dict[str, Any] = field(default_factory=dict)
     enabled: bool = True
     optional: bool = False
 
@@ -59,17 +59,17 @@ class Connection:
 
     source: str
     target: str
-    data_type: Optional[str] = None  # Optional data type constraint
+    data_type: str | None = None  # Optional data type constraint
 
 
 @dataclass
 class Graph:
     """Pipeline graph representation."""
 
-    nodes: Dict[str, Node] = field(default_factory=dict)
-    connections: List[Connection] = field(default_factory=list)
+    nodes: dict[str, Node] = field(default_factory=dict)
+    connections: list[Connection] = field(default_factory=list)
 
-    def node(self, name: str, node_type: Union[NodeType, str], **config) -> "Graph":
+    def node(self, name: str, node_type: NodeType | str, **config) -> "Graph":
         """Add a node to the graph."""
         if isinstance(node_type, str):
             # Try to parse as NodeType
@@ -82,7 +82,7 @@ class Graph:
         return self
 
     def connect(
-        self, source: str, target: str, data_type: Optional[str] = None
+        self, source: str, target: str, data_type: str | None = None
     ) -> "Graph":
         """Add a connection between nodes."""
         if source not in self.nodes:
@@ -99,7 +99,7 @@ class Graph:
             self.connect(names[i], names[i + 1])
         return self
 
-    def from_dict(self, data: Dict[str, Any]) -> "Graph":
+    def from_dict(self, data: dict[str, Any]) -> "Graph":
         """Load graph from dictionary (TOML-compatible)."""
         # Parse nodes
         nodes_data = data.get("nodes", {})
@@ -127,7 +127,7 @@ class Graph:
 
         return self
 
-    def to_dict(self) -> Dict[str, Any]:
+    def to_dict(self) -> dict[str, Any]:
         """Convert graph to dictionary."""
         return {
             "nodes": {
@@ -140,7 +140,7 @@ class Graph:
             ],
         }
 
-    def validate(self) -> List[str]:
+    def validate(self) -> list[str]:
         """Validate graph structure and return list of errors."""
         errors = []
 
@@ -166,9 +166,8 @@ class Graph:
 
             temp.add(node_name)
             for conn in self.connections:
-                if conn.source == node_name:
-                    if has_cycle(conn.target):
-                        return True
+                if conn.source == node_name and has_cycle(conn.target):
+                    return True
             temp.remove(node_name)
             visited.add(node_name)
             return False