Improve OpenCode PR review with MCP-backed inline suggestions

[LiusCraft]

Background

• The current OpenCode PR review workflow gives only generic feedback and does not consistently use inline review comments.
• We need review behavior that is higher-signal, bug-first, and better aligned with actionable GitHub review UX.

Changes

• Updated .github/workflows/opencode-pr-review.yml to wire GitHub MCP remote server config into OpenCode via OPENCODE_CONFIG_CONTENT.
• Added token handling with GITHUB_MCP_TOKEN (secrets.GITHUB_MCP_PAT fallback to github.token) and enabled use_github_token: true.
• Replaced the prompt with a stricter review protocol: AGENTS.md-aware checks, high-confidence issue filtering, required inline review flow, and suggestion-block usage guidance.

Behavior Impact

• Automated reviews now instruct the agent to create pending reviews, add inline comments on exact diff lines, and submit the review.
• For small self-contained fixes, comments can include GitHub suggestion blocks to make fixes one-click applicable.
• Existing trigger events and job permissions remain unchanged.

Risks and Rollback

• Risk: Inline review behavior depends on MCP tool availability and token scopes; limited scopes may reduce functionality.
• Risk: Stricter prompt may reduce comment volume and omit low-confidence findings by design.
• Rollback: Revert .github/workflows/opencode-pr-review.yml to the previous prompt/env configuration and rerun workflow.

Verification

• Parsed workflow YAML successfully using: ruby -e 'require "yaml"; YAML.load_file(".github/workflows/opencode-pr-review.yml")'.
• Could not run full GitHub Actions execution locally because workflow runtime and PR events are GitHub-hosted.

Notes

• GITHUB_MCP_PAT is optional; when absent the workflow falls back to GITHUB_TOKEN.
• Reviewer focus: confirm inline comments appear on changed lines and suggestion blocks are used only for fully-contained fixes.

[github-actions]

No issues found. Checked for bugs and AGENTS.md compliance.

The workflow changes are correct:

• MCP configuration follows OpenCode schema and GitHub documentation
• Token handling with fallback is properly implemented
• Prompt changes are well-structured for bug-first review process

opencode session  |  github run

[github-actions]

Based on my review, I found no issues. The changes are correct:

1. YAML/JSON syntax: Valid - passes Ruby YAML parser and embedded JSON parser
2. OpenCode MCP config: Valid - follows official OpenCode MCP documentation (type: "remote", correct URL format https://api.githubcopilot.com/mcp/, proper headers)
3. GitHub MCP URL: Correct - verified against GitHub's official documentation
4. Token handling: Correct - uses secrets.GITHUB_MCP_PAT || github.token fallback pattern
5. Permissions: Properly configured (pull-requests: write needed for inline comments)
6. AGENTS.md compliance: No specific rules apply to GitHub workflow files in this repo

opencode session  |  github run