Fix stale plugin disable handling and BSD grep regex fallback

[hawkff]

What

This PR includes two reliability fixes for cursor-acp on OpenCode:

1. Respect plugin disable state in OpenCode config

• plugin entrypoint now checks opencode.json before initializing
• if cursor-acp is removed from the plugin array, plugin init is skipped (no-op)
• supports config path resolution via:
  • OPENCODE_CONFIG
  • XDG_CONFIG_HOME
  • ~/.config/opencode/opencode.json

2. Fix BSD/macOS grep regex failures in tool hook

• grep tool now retries with -E when default regex mode returns syntax errors (code=2)
• handles BSD variants such as:
  • invalid repetition count
  • braces not balanced
  • Unmatched {
• keeps existing behavior for no-match (code=1 => No matches found)

Why

• Users removing cursor-acp from the config plugin array could still get plugin/runtime errors if the plugin symlink remained present.
• On macOS/BSD grep, some model-generated patterns fail in basic regex mode, causing noisy Tool hook execution failed warnings.

Validation

• bun run build
• bun run test:ci:unit
• bun run test:ci:integration

All pass on the fork’s main.

Files

• src/plugin-entry.ts
• src/plugin-toggle.ts
• src/tools/defaults.ts
• tests/unit/plugin-toggle.test.ts
• tests/tools/defaults.test.ts
• tests/competitive/edge.test.ts
• tests/integration/comprehensive.test.ts

[Nomadcxx]

Thanks again for this PR — this was very helpful.

I closed this as superseded because the branch became a stacked umbrella and now conflicts with current main after other merges. I opened and merged a focused replacement PR that ports the two still-relevant fixes cleanly on top of current main:

• plugin-entry disable guard (respect plugin array in opencode.json)
• BSD/macOS grep regex fallback (-E retry on code=2 regex syntax errors)

Merged replacement: #24
#24

Credit preserved: the ported commit keeps original attribution and references your source commits.