0006. Settings apply instantly; no draft copy

• Status: Accepted
• Date: 2026-10-09
• Deciders: tseka

Context

ChartSettingsDialog.vue holds a local draft (settings = ref(loadSettings()), :383) that is committed on 确定 (:408). Theme presets bypass it and apply immediately (:413). This creates a derived copy and two write paths. Both are rejected by the README principles ("The Agent is the user"; StateKernel single source of truth). If an Agent changes a setting while the dialog is open, the stale draft overwrites the Agent's change.

Platform guidance (Microsoft settings guidelines, cited in the task research trading-ui-benchmark.md §4.2) also prefers instant apply.

Decision

• Every settings control dispatches the same action the Agent would. There is no dialog-local draft.
• Remove 重置 / 取消 / 确定. The dialog closes with × or Esc.
• Each section has 恢复默认 (restore defaults), followed by an Undo toast.
• Explicit commit is kept only for credential forms (data-source keys), scoped to that form.
• The nested color-preset modal becomes an inline expander.

Consequences

• Settings become observable and agent-addressable like any other action.
• Undo is required on reset paths.
• E2E tests cover "Agent changes a setting while the dialog is open".