fix(opencode): strip tools array from cavecrew agent frontmatter

[ousamabenyounes]

Fixes #386

Summary

OpenCode rejects YAML array form tools: [...] for subagent frontmatter and refuses to boot:

Configuration is invalid at .../cavecrew-reviewer.md
↳ Expected object | undefined, got ["Read","Grep","Bash"] tools

installOpencode() in bin/install.js copied agents/cavecrew-*.md verbatim into ~/.config/opencode/agents/. Three files affected: cavecrew-investigator.md, cavecrew-builder.md, cavecrew-reviewer.md.

Fix

New helper bin/lib/opencode-agent.js exports stripOpencodeAgentTools(content) that removes the tools: line (inline-array form and multi-line YAML list form) from the leading frontmatter block. Installer's section 3 now reads → strips → writes instead of copyFileSync.

OpenCode allows omitting tools entirely; it then falls back to its default tool set. The cavecrew subagent prompts already self-restrict in the body ("Read-only locator", "No Bash available", etc.), so dropping the array form is safe.

Source files in agents/ are left untouched — they keep the Claude Code schema for the Claude Code plugin path. Transform applies only on the OpenCode copy.

Verification

Baseline (main): 47 pass / 4 fail / 51 total — 4 pre-existing opencode failures (caveman-compress.md missing in src/plugins/opencode/commands/, separate issue).

Post-fix: 56 pass / 4 fail / 60 total — 9 new tests, zero regressions, same 4 pre-existing failures.

TDD verification

• RED check (helper missing): test file fails to import → 0/1.
• GREEN check (helper present): 9/9 pass.

Logs persisted locally in ~/.claude/contribute/working/caveman/issue_386_{RED,GREEN}.log.

Files changed

File	Change
bin/lib/opencode-agent.js	New. stripOpencodeAgentTools() helper.
bin/install.js	Section 3 of installOpencode now sanitizes on copy.
tests/installer/opencode-agent.test.mjs	New. 9 tests: inline array, multi-line list, folded description: >, no-frontmatter, no-tools, non-string, real shipped files RED/GREEN, end-to-end installer-equivalent copy.

[ousamabenyounes]

Verified RED/GREEN proof (run on 8014b87 against origin/main)

Test runner: node --test tests/installer/opencode-agent.test.mjs.

Procedure:

1. GREEN — full PR diff applied
2. Replace bin/lib/opencode-agent.js with an identity stub (preserves the require resolution so unrelated tests still load, kills the strip-behavior so any test that depends on it fails)
3. RED — same test file
4. Restore helper byte-identical

GREEN (fix applied)

# tests 9
# pass 9
# fail 0

RED (helper neutered to identity)

# tests 9
# pass 4
# fail 5

The 5 failing tests on RED are precisely the ones that exercise the strip-behavior:

• strips inline tools: [...] array from frontmatter
• strips multi-line tools: list with indented continuation
• preserves folded description: > continuation lines when tools: follows
• all shipped cavecrew agent files become OpenCode-safe after transform (GREEN proof)
• installer-equivalent copy writes OpenCode-safe agent file (issue 386 end-to-end)

The 4 tests that pass on RED are deliberate pass-through guards (no frontmatter, no tools: field, non-string input, and the RED-proof check that asserts the source agents/cavecrew-*.md files contain the offending array form — which is a property of the source tree, independent of the helper).

Both logs captured locally and available on request.