D-15: ToolCallCardView — generic card with lifecycle animations

[kirich1409]

Description

Implement the generic ToolCallCardView — the shell that renders any tool call (Read / Edit / Bash / MCP / etc.) with consistent lifecycle animations (pending → in_progress → completed / failed). Specialized content per tool kind is injected via a slot (see D-16).

Spec: Epic #250 §6 (UI concept — tool-call level live feel).

Scope

File

MacApp/Packages/AgentChatUI/Sources/AgentChatUI/ToolCall/ToolCallCardView.swift

Structure

```swift
public struct ToolCallCardView<Content: View>: View {
public init(
toolCall: ToolCall,
@ViewBuilder content: @escaping (ToolCall) -> Content
)
}
```

• Uses Card(style: .emphasized) from DS.
• Header row: icon (per ToolKind) + tool name + StatusIndicator(kind:) (per status) + optional live duration ("2s").
• Body: injected via content builder (specialized widget for this tool).
• Collapsible — default state: pending/in_progress expanded, completed/failed collapsed (click to expand).
• Animations (all accessibilityReduceMotion-guarded):
  • pending: shimmer skeleton (placeholder content);
  • in_progress: subtle pill opacity pulse (opacity 0.7 ↔ 1.0, 0.8s cycle);
  • completed: checkmark spring (scale 0.8 → 1.0, DS.Motion.fast);
  • failed: shake (horizontal offset ±4pt, DS.Motion.fast, 2 cycles), red border.

Live duration

While status == .inProgress(startedAt:):

• TimelineView(.periodic(from: .now, by: 1)) updates a "2s / 10s / 1m 3s" label in the header every second.
• Stops when status transitions.

Error presentation

.failed(at:reason:) — red DS.Color.destructive border, warning SF Symbol in status indicator, reason string in body.

Accessibility

• .accessibilityLabel: "Tool call: {tool_name}, status {status.description}".
• .accessibilityValue: status + duration.
• Live region announce on status transitions (pending → in_progress → completed / failed).
• Shake animation for .failed — guarded by reduceMotion (skip animation, only red border remains).

Acceptance Criteria

• ToolCallCardView implemented with generic content slot.
• All four status states render distinctly (pending / in_progress / completed / failed).
• Live duration counter ticks accurately (verified with unit test on TimelineView).
• Animations wrapped in accessibilityReduceMotion — under reduceMotion: no pulse, no shake, no spring (fade only).
• Collapse/expand: pending/in_progress expanded by default; completed/failed collapsed by default; click toggles.
• .textSelection(.enabled) on content (user can copy tool output).
• VoiceOver announces status changes; reads "completed" / "failed" accurately.
• Snapshot tests — all 4 statuses × 4 appearances (light / dark / HCR / reduceTransparency).
• No hardcoded values — DS tokens only.

Relationships

• Parent issue: EPIC: Dialogue — structured chat UI for agent sessions #250
• Blocked by: D-1: DesignSystem — add Card primitive #251 (Card), D-2: DesignSystem — add StatusIndicator primitive #252 (StatusIndicator), #D-12
• Blocks: #D-16, #D-14