[BUG] code-review plugin subagents fail silently on PRs with large diffs (>25K tokens)

Description

The code-review@claude-code-plugins plugin (used via anthropics/claude-code-action@v1) silently produces zero review comments on PRs where the unified diff exceeds ~25,000 tokens (~75KB).

Steps to Reproduce

1. Configure claude-code-action@v1 with the code-review plugin:

``yaml
uses: anthropics/claude-code-action@v1
with:
plugins: 'code-review@claude-code-plugins'
prompt: '/code-review:code-review owner/repo/pull/N'
claude_args: '--max-turns 25'
show_full_output: true
``

1. Open a PR with ~2,000 lines changed across 23 files (~120KB / ~41K tokens unified diff)
2. Review runs to completion (green check) but posts zero comments

Root Cause (from log analysis)

The plugin architecture:

1. Pre-flight check passes ("CONTINUE - PR needs review")
2. Summary subagent completes
3. 4 review subagents launched in parallel (2 CLAUDE.md compliance, 2 bug detection)
4. Each subagent runs gh pr diff N → output exceeds Bash tool limit → persisted to file
5. Subagents try to Read the persisted file → "File content (41722 tokens) exceeds maximum allowed tokens (25000)"
6. Subagents spend all their turns trying to paginate with offset/limit, then hit their internal turn limit
7. No subagent ever returns results → main agent never reaches the pr-comments posting step
8. Action exits successfully with zero output

Key Details

• --max-turns 25 only controls the main agent's turns, not the subagent turn limits
• Increasing --max-turns from default to 25 extended subagent runtime from ~3 min to ~6 min but didn't resolve
• The pr-comments tool is listed as available but never invoked in any run
• The action reports success (exit 0) despite producing no review

Expected Behavior

• Subagents should chunk or paginate large diffs without exhausting their turn budget
• Or: the plugin should fall back to per-file diff review when the full diff exceeds the Read tool limit
• Or: the action should report a warning/failure when no review comments were produced despite a non-empty diff

Environment

• anthropics/claude-code-action@v1
• code-review@claude-code-plugins from marketplace https://github.com/anthropics/claude-code.git
• PR: ~23 files, ~2,000 lines, ~120KB unified diff (~41K tokens)

Workaround

None currently. The plugin works fine for smaller PRs (estimated <25K tokens / <75KB diff). Large PRs silently get no review.