feat: enable 'always approve for session' for runtime tools

Runtime tool permission requests (read, write, shell, store_memory) now
resolve stable approval names via fallback in the sidecar approval
coordinator, enabling the 'Always approve' button and session-level
auto-approval for built-in tools.

Backend:
- Add fallback tool names for PermissionRequestRead (read),
  PermissionRequestWrite (write), PermissionRequestShell (shell),
  and PermissionRequestMemory (store_memory)
- Add autoApprovedToolName parameter to RequiresToolCallApproval
  for permission-kind-based session approval matching
- Track tool.execution_start events in ToolNamesByCallId for
  supplementary exact-name resolution

Frontend:
- Use approval.toolName ?? approval.permissionKind as fallback key
  in resolveSessionApproval and ApprovalBanner
- Add shell, read, write permission-kind entries to builtin approval
  tool definitions so pruning preserves session overrides

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

sidecar/src/Aryx.AgentHost/Services/CopilotTurnExecutionState.cs

@@ -77,6 +77,11 @@ internal sealed class CopilotTurnExecutionState
                 RecordObservedAgentForMessage(agent, assistantMessage.Data!.MessageId);
                 QueueThinkingIfNeeded(agent);
                 break;
+            case ToolExecutionStartEvent toolExecutionStart
+                when !string.IsNullOrWhiteSpace(toolExecutionStart.Data?.ToolCallId)
+                    && !string.IsNullOrWhiteSpace(toolExecutionStart.Data?.ToolName):
+                ToolNamesByCallId[toolExecutionStart.Data.ToolCallId.Trim()] = toolExecutionStart.Data.ToolName.Trim();
+                break;
             case AssistantReasoningDeltaEvent:
                 ActiveAgent = agent;
                 QueueThinkingIfNeeded(agent);