[VSCode extension] Allow configuring permission mode after plan approval

Problem

When using Plan mode in the Claude Code VSCode extension, approving a plan (via ExitPlanMode) always transitions to acceptEdits ("Edit automatically") mode. This is hardcoded with no configuration option.

For users who already run with claudeCode.allowDangerouslySkipPermissions: true and prefer to skip per-action permission prompts after reviewing a plan, this forces an extra manual step (Shift+Tab cycle or panel toggle) every time.

Current settings (extension v2.1.175)

• claudeCode.initialPermissionMode — controls only the initial mode
• claudeCode.allowDangerouslySkipPermissions — enables bypass as an option

Neither lets you choose what mode is entered after plan approval.

Proposed

Add either of:

1. claudeCode.postPlanPermissionMode in the VSCode extension config, with the same enum as initialPermissionMode: default | acceptEdits | plan | bypassPermissions

1. postPlanMode in ~/.claude/settings.json so it applies to all surfaces (CLI and VSCode).

Default value should remain acceptEdits to preserve current behavior.

Use case

Plan mode as default + bypass after approval = safe two-step workflow (plan review → autonomous execution) without manual mode switching between each task.