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/tests/Aryx.AgentHost.Tests/CopilotTurnExecutionStateTests.cs

@@ -58,6 +58,31 @@ public sealed class CopilotTurnExecutionStateTests
         Assert.Equal("agent-1", observedAgent.AgentId);
     }
 
+    [Fact]
+    public void ObserveSessionEvent_ToolExecutionStart_TracksToolNameByCallId()
+    {
+        RunTurnCommandDto command = CreateCommand();
+        CopilotTurnExecutionState state = new(command);
+
+        state.ObserveSessionEvent(
+            command.Pattern.Agents[0],
+            SessionEvent.FromJson(
+                """
+                {
+                  "type": "tool.execution_start",
+                  "data": {
+                    "toolCallId": "tool-call-1",
+                    "toolName": "view"
+                  },
+                  "id": "33333333-3333-3333-3333-333333333333",
+                  "timestamp": "2026-03-27T00:00:00Z"
+                }
+                """));
+
+        Assert.True(state.ToolNamesByCallId.TryGetValue("tool-call-1", out string? toolName));
+        Assert.Equal("view", toolName);
+    }
+
     [Fact]
     public async Task EmitThinkingIfNeeded_DoesNotDuplicateQueuedThinkingActivity()
     {

sidecar/tests/Aryx.AgentHost.Tests/CopilotWorkflowRunnerTests.cs

@@ -766,7 +766,29 @@ public sealed class CopilotWorkflowRunnerTests
     }
 
     [Fact]
-    public void TryGetApprovalToolName_ReadsMcpCustomAndHookRequests()
+    public void RequiresToolCallApproval_HonorsRuntimeApprovalAliases()
+    {
+        ApprovalPolicyDto policy = new()
+        {
+            Rules =
+            [
+                new ApprovalCheckpointRuleDto
+                {
+                    Kind = "tool-call",
+                    AgentIds = ["agent-1"],
+                },
+            ],
+            AutoApprovedToolNames = ["read", "store_memory"],
+        };
+
+        Assert.False(CopilotApprovalCoordinator.RequiresToolCallApproval(policy, "agent-1", "view", "read"));
+        Assert.False(CopilotApprovalCoordinator.RequiresToolCallApproval(policy, "agent-1", "remember_fact", "store_memory"));
+        Assert.True(CopilotApprovalCoordinator.RequiresToolCallApproval(policy, "agent-1", "write_file", "write"));
+        Assert.True(CopilotApprovalCoordinator.RequiresToolCallApproval(policy, "agent-1", "git.status"));
+    }
+
+    [Fact]
+    public void TryGetApprovalToolName_ResolvesDirectNamesAndRuntimeFallbacks()
     {
         Assert.True(
             CopilotApprovalCoordinator.TryGetApprovalToolName(
@@ -804,7 +826,7 @@ public sealed class CopilotWorkflowRunnerTests
                 out string? hookToolName));
         Assert.Equal("web_fetch", hookToolName);
 
-        Assert.False(
+        Assert.True(
             CopilotApprovalCoordinator.TryGetApprovalToolName(
                 new PermissionRequestShell
                 {
@@ -818,7 +840,49 @@ public sealed class CopilotWorkflowRunnerTests
                     CanOfferSessionApproval = false,
                 },
                 out string? shellToolName));
-        Assert.Null(shellToolName);
+        Assert.Equal("shell", shellToolName);
+    }
+
+    [Fact]
+    public void TryGetApprovalToolName_FallsBackToRuntimeApprovalAliasesWhenLookupMissing()
+    {
+        Assert.True(
+            CopilotApprovalCoordinator.TryGetApprovalToolName(
+                new PermissionRequestRead
+                {
+                    Kind = "read",
+                    ToolCallId = "tool-call-read",
+                    Intention = "Inspect a file",
+                    Path = "README.md",
+                },
+                out string? readToolName));
+        Assert.Equal("read", readToolName);
+
+        Assert.True(
+            CopilotApprovalCoordinator.TryGetApprovalToolName(
+                new PermissionRequestWrite
+                {
+                    Kind = "write",
+                    ToolCallId = "tool-call-write",
+                    Intention = "Update a file",
+                    FileName = "README.md",
+                    Diff = "@@ -1 +1 @@",
+                },
+                out string? writeToolName));
+        Assert.Equal("write", writeToolName);
+
+        Assert.True(
+            CopilotApprovalCoordinator.TryGetApprovalToolName(
+                new PermissionRequestMemory
+                {
+                    Kind = "memory",
+                    ToolCallId = "tool-call-memory",
+                    Subject = "repo conventions",
+                    Fact = "Use Bun for script execution.",
+                    Citations = "package.json",
+                },
+                out string? memoryToolName));
+        Assert.Equal("store_memory", memoryToolName);
     }
 
     [Fact]