Add sessionId to all hook input types consistently across Python and .NET

- Python: Add sessionId to UserPromptSubmittedHookInput, SessionStartHookInput,
  SessionEndHookInput, ErrorOccurredHookInput. Remove unused BaseHookInput.
- .NET: Add SessionId to UserPromptSubmittedHookInput, SessionStartHookInput,
  SessionEndHookInput, ErrorOccurredHookInput.

All 6 hook input types now have sessionId in every SDK (Node, Python, Go, .NET, Rust).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: SteveSandersonMS

dotnet/src/Types.cs

@@ -1253,6 +1253,12 @@ public class PostToolUseHookOutput
 /// </summary>
 public class UserPromptSubmittedHookInput
 {
+    /// <summary>
+    /// The runtime session ID of the session that triggered the hook.
+    /// </summary>
+    [JsonPropertyName("sessionId")]
+    public string SessionId { get; set; } = string.Empty;
+
     /// <summary>
     /// Unix timestamp in milliseconds when the prompt was submitted.
     /// </summary>
@@ -1306,6 +1312,12 @@ public class UserPromptSubmittedHookOutput
 /// </summary>
 public class SessionStartHookInput
 {
+    /// <summary>
+    /// The runtime session ID of the session that triggered the hook.
+    /// </summary>
+    [JsonPropertyName("sessionId")]
+    public string SessionId { get; set; } = string.Empty;
+
     /// <summary>
     /// Unix timestamp in milliseconds when the session started.
     /// </summary>
@@ -1364,6 +1376,12 @@ public class SessionStartHookOutput
 /// </summary>
 public class SessionEndHookInput
 {
+    /// <summary>
+    /// The runtime session ID of the session that triggered the hook.
+    /// </summary>
+    [JsonPropertyName("sessionId")]
+    public string SessionId { get; set; } = string.Empty;
+
     /// <summary>
     /// Unix timestamp in milliseconds when the session ended.
     /// </summary>
@@ -1436,6 +1454,12 @@ public class SessionEndHookOutput
 /// </summary>
 public class ErrorOccurredHookInput
 {
+    /// <summary>
+    /// The runtime session ID of the session that triggered the hook.
+    /// </summary>
+    [JsonPropertyName("sessionId")]
+    public string SessionId { get; set; } = string.Empty;
+
     /// <summary>
     /// Unix timestamp in milliseconds when the error occurred.
     /// </summary>

python/copilot/session.py

@@ -610,14 +610,6 @@ async def input(self, message: str, options: InputOptions | None = None) -> str
 # ============================================================================
 
 
-class BaseHookInput(TypedDict):
-    """Base interface for all hook inputs"""
-
-    sessionId: str
-    timestamp: int
-    cwd: str
-
-
 class PreToolUseHookInput(TypedDict):
     """Input for pre-tool-use hook"""
 
@@ -672,6 +664,7 @@ class PostToolUseHookOutput(TypedDict, total=False):
 class UserPromptSubmittedHookInput(TypedDict):
     """Input for user-prompt-submitted hook"""
 
+    sessionId: str
     timestamp: int
     cwd: str
     prompt: str
@@ -694,6 +687,7 @@ class UserPromptSubmittedHookOutput(TypedDict, total=False):
 class SessionStartHookInput(TypedDict):
     """Input for session-start hook"""
 
+    sessionId: str
     timestamp: int
     cwd: str
     source: Literal["startup", "resume", "new"]
@@ -716,6 +710,7 @@ class SessionStartHookOutput(TypedDict, total=False):
 class SessionEndHookInput(TypedDict):
     """Input for session-end hook"""
 
+    sessionId: str
     timestamp: int
     cwd: str
     reason: Literal["complete", "error", "abort", "timeout", "user_exit"]
@@ -740,6 +735,7 @@ class SessionEndHookOutput(TypedDict, total=False):
 class ErrorOccurredHookInput(TypedDict):
     """Input for error-occurred hook"""
 
+    sessionId: str
     timestamp: int
     cwd: str
     error: str