D-2: DesignSystem — add StatusIndicator primitive

[kirich1409]

Description

Add StatusIndicator — generic pill / dot component for rendering tool-call lifecycle states (pending / in_progress / completed / failed) and session status (idle / streaming / thinking / error). Used by ToolCallCardView, top status strip in DialogueView, and tab-icon indicators.

⚠️ Re-verify before implementation. DS already ships StatusBadge (Components/StatusBadge.swift) with SF Symbol + label + color-coded states. Before creating a new StatusIndicator, check whether StatusBadge already covers the required kinds (idle / pending / inProgress / completed / failed / warning) and sizes (dot / pill / large). If yes — extend StatusBadge with missing variants instead of duplicating. A new type only makes sense if animation / accessibility / sizing requirements don't fit the existing API.

Spec: Epic #250 §6 (UI concept — live feel).

Scope

Either extend StatusBadge with missing variants or create StatusIndicator (decide based on API fit):

public enum Kind: Equatable, Sendable {
    case idle
    case pending        // subtle pulse
    case inProgress     // animated spinner
    case completed      // static checkmark
    case failed         // static warning icon
    case warning        // yellow pulse
}
public enum Size { case dot, pill, large }
// public init(kind: Kind, size: Size = .pill, label: LocalizedStringKey? = nil)

• dot — 8pt circle, no label.
• pill — icon + optional label + inline color fill (using SF Symbol + DS.Color.{success, warning, destructive, textSecondary}).
• large — headline-sized badge for top status strip.
• Every Kind pairs color + SF Symbol + animation (never color alone — a11y req).
• Animations wrapped in @Environment(\.accessibilityReduceMotion) — when on, spinner becomes static icon, pulse becomes fade-in only.
• All sizes have .accessibilityLabel from Kind.description and .accessibilityValue reflecting active state.

Acceptance Criteria

• Decision recorded: extend StatusBadge or create StatusIndicator (with rationale vs existing API).
• Chosen approach implements Kind, Size, public init(kind:size:label:).
• Each of 6 Kinds renders a unique icon + color + motion signature — no color-only signaling.
• All animations conditionally guarded by accessibilityReduceMotion.
• .accessibilityLabel present and meaningful for every combination.
• Added to DesignSystemCatalog with all 6 kinds × 3 sizes × light/dark/HCR/reduceTransparency.
• Owner approval for ds-api.
• Unit tests cover kind→icon and kind→a11y-label mappings.

Relationships

• Parent issue: EPIC: Dialogue — structured chat UI for agent sessions #250
• Blocks: #D-15 (ToolCallCardView), #D-18 (DialogueView status strip), #D-14 (AssistantMessageView streaming indicator)