Effort level 'max' should be persistable in settings.json for Max plan subscribers

Problem

Max plan subscribers ($200/month) cannot persist the "max" effort level in settings.json. After every "Clear Conversation" in VSCode extension, effort resets from 99/100 back to 85/100 ("high"), requiring manual slider adjustment each time.

Current behavior

1. settings.json with "effortLevel": "high" → effort 85/100 ✅ (persists)
2. settings.json with "effortLevel": "max" → effort 85/100 (treated as "high", no error)
3. CLI --effort max → rejected: Error: Effort level "max" is not available for Claude.ai subscribers
4. UI slider → can be set to max (99/100) ✅ but resets after Clear Conversation

Expected behavior

Max plan subscribers should be able to set "effortLevel": "max" in settings.json and have it persist across conversation clears, just like the model setting persists.

The VSCode extension webview already supports 4 effort levels internally ({low:1, medium:2, high:3, max:4}), but the CLI validation blocks "max" for Claude.ai subscribers, causing a mismatch.

Workaround

After every Clear Conversation, manually click the effort slider to set it back to max. This is needed ~50 times/day for active users.

Environment

• Claude Code VSCode Extension v2.1.74
• Max plan subscriber
• Windows 11
• Settings configured in both ~/.claude/settings.json and .claude/settings.json