SDK 0.2.15 causes AJV validation error - Claude Code Review fails immediately

## Description

After the `@anthropic-ai/claude-agent-sdk` was updated from `0.2.9` to `0.2.15`, all Claude Code Review runs fail immediately with an AJV JSON schema validation error.

## Reproduction

Any PR review using `anthropics/claude-code-action@v1` that picks up SDK version 0.2.15.

**Repository:** https://github.com/science-of-people/sop-agents
**PR:** https://github.com/science-of-people/sop-agents/pull/53

## Evidence

### Successful run (SDK 0.2.9) - Jan 21, 2026
- Run: https://github.com/science-of-people/sop-agents/actions/runs/21217320542
- SDK version: `@anthropic-ai/claude-agent-sdk@0.2.9`
- Duration: 3m53s
- Result: ✅ Success

### Failing run (SDK 0.2.15) - Jan 22, 2026
- Run: https://github.com/science-of-people/sop-agents/actions/runs/21249684715
- SDK version: `@anthropic-ai/claude-agent-sdk@0.2.15`
- Duration: 26s
- Result: ❌ Failure

## Error Output

```json
{
"type": "result",
"subtype": "success",
"is_error": true,
"duration_ms": 261,
"num_turns": 1,
"total_cost_usd": 0,
"permission_denials": []
}
```

```
SDK execution error: 14 | depsCount: ${Q},
15 | deps: ${$}}`};var Mj={keyword:"dependencies",type:"object",schemaType:"object",error:RB.error,code(X){let[Q,$]=jj(X);MB(X,Q),jB(X,$)}};function jj({schema:X}){...

error: Claude Code process exited with code 1
at $ (/home/runner/work/_actions/anthropics/claude-code-action/v1/base-action/node_modules/@anthropic-ai/claude-agent-sdk/sdk.mjs:19:7668)
```

## Analysis

- The error is from AJV (JSON Schema validator) - specifically the "dependencies" keyword validation
- Claude Code initializes successfully but fails on turn 1 with 0 API cost
- The same codebase was passing with SDK 0.2.9
- No code changes in the repository correlate with the failure - only the SDK version change

## Workflow Configuration

```yaml
- name: Run Claude Code Review
uses: anthropics/claude-code-action@v1
with:
claude_code_oauth_token: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
claude_args: '--allowed-tools "Bash(gh issue view:*),Bash(gh search:*),Bash(gh issue list:*),Bash(gh pr comment:*),Bash(gh pr diff:*),Bash(gh pr view:*),Bash(gh pr list:*)"'
```

## Expected Behavior

Claude Code Review should complete successfully as it did with SDK 0.2.9.

## Environment

- Runner: ubuntu-latest (Ubuntu 24.04.3)
- Action: `anthropics/claude-code-action@v1`
- Model: `claude-sonnet-4-5-20250929`