[Feature Request] Add auto-continue option for Plan Mode phases

Bug Description
Auto-continue option for Plan Mode phases

### Current Behavior
When using plan mode, Claude Code stops after each phase (Initial Understanding → Design → Review → Final Plan) and asks the user for confirmation before proceeding to the next phase. This requires multiple user interactions to complete a single planning session.

### Pain Point
When working on familiar codebases or straightforward tasks, the frequent pauses between phases interrupt the workflow. Users who trust the planning process often just keep pressing Enter to continue, making these pauses feel unnecessary.

### Requested Feature
Add a configuration option to allow plan mode to automatically proceed through all phases without intermediate confirmations. For example:

```json
{
"planMode": {
"autoContinue": true
}
}

Or a flag like --plan-auto-continue for CLI usage.

Use Cases

1. Experienced users who prefer to review the final plan rather than each intermediate step
2. CI/CD pipelines or automated workflows that use plan mode
3. Users working on well-understood codebases where they trust Claude's exploration

Suggested Behavior

• When autoContinue is enabled, Claude completes all phases and only stops at the final ExitPlanMode step for user approval
• Users can still interrupt at any point with Ctrl+C if needed
• The intermediate phase outputs would still be visible in the terminal for transparency

Alternative Approaches

1. A "fast plan" mode that combines phases
2. A configurable list of phases that require confirmation
3. A timeout-based auto-continue (e.g., continue after 3 seconds if no input)

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.1.6
• Feedback ID: 235e6889-e270-4c4d-8fcf-a013bedfa006

Errors

[{"error":"Error: 1P event logging: 1 events failed to export\n    at Va1.queueFailedEvents (file:///Users/wukai/.nvm/versions/node/v18.18.2/lib/node_modules/@anthropic-ai/claude-code/cli.js:260:2038)\n    at async Va1.doExport (file:///Users/wukai/.nvm/versions/node/v18.18.2/lib/node_modules/@anthropic-ai/claude-code/cli.js:260:1195)","timestamp":"2026-01-13T06:54:18.275Z"},{"error":"Error: {\"stack\":\"Error: Failed to export 1 events\\n    at Va1.doExport (file:///Users/wukai/.nvm/versions/node/v18.18.2/lib/node_modules/@anthropic-ai/claude-code/cli.js:260:1297)\",\"message\":\"Failed to export 1 events\",\"name\":\"Error\"}\n    at e$0.error (file:///Users/wukai/.nvm/versions/node/v18.18.2/lib/node_modules/@anthropic-ai/claude-code/cli.js:2740:34862)\n    at Pi1.error (file:///Users/wukai/.nvm/versions/node/v18.18.2/lib/node_modules/@anthropic-ai/claude-code/cli.js:254:10496)\n    at file:///Users/wukai/.nvm/versions/node/v18.18.2/lib/node_modules/@anthropic-ai/claude-code/cli.js:254:41521\n    at yh3 (file:///Users/wukai/.nvm/versions/node/v18.18.2/lib/node_modules/@anthropic-ai/claude-code/cli.js:254:42067)\n    at file:///Users/wukai/.nvm/versions/node/v18.18.2/lib/node_modules/@anthropic-ai/claude-code/cli.js:255:20245","timestamp":"2026-01-13T06:54:18.275Z"}]