fix(config): parse markdown prompt file blocks as prompts

[rodboev]

Fixes #12412

Summary

Markdown files referenced from config.yaml prompts blocks are currently resolved but then dropped, because markdown fallback parsing always wraps the file as a rule. This changes block unrolling so markdown files resolved for the prompts section become prompt blocks instead.

Root cause

packages/config-yaml/src/load/unroll.ts:436-441 resolves uses blocks and then reads the array for the current section, such as blockConfigYaml.prompts. But resolveBlock parses markdown fallback content through parseMarkdownRuleOrAssistantUnrolled, and parseYamlOrMarkdownRule at unroll.ts:798-802 always wraps markdown as { rules: [...] }. For a prompts block, that leaves blockConfigYaml.prompts undefined, so the prompt is silently skipped.

Changes

• packages/config-yaml/src/markdown/parseMarkdownPrompt.ts: add a small markdown prompt parser that preserves frontmatter name, description, prompt body, and source file.
• packages/config-yaml/src/markdown/index.ts: export the prompt parser.
• packages/config-yaml/src/load/unroll.ts: pass the target section into resolved block parsing and wrap markdown prompt files under prompts.
• packages/config-yaml/src/load/unroll.test.ts: cover markdown prompt block unrolling and existing markdown rule fallback.

What this doesn't change

This does not change YAML prompt blocks, injected blocks, or local prompt-file discovery in core/config/yaml/loadYaml.ts. It also keeps markdown fallback as rules for non-prompts sections.

Checklist

• I've read the contributing guide
• The relevant docs, if any, have been updated or created
• The relevant tests, if any, have been updated or created

Screen recording or screenshot

N/A, no UI change.

Tests

• cd packages/config-yaml && npm test -- src/load/unroll.test.ts — blocked before this test file executes by existing TS7006 diagnostics in src/converter.ts on unchanged origin/main lines.
• cd packages/config-yaml && cross-env NODE_OPTIONS=--experimental-vm-modules npx jest src/load/unroll.test.ts --globals '{"ts-jest":{"diagnostics":false}}' — 30/30 passing. Covers markdown prompt block unrolling, frontmatter parsing, filename fallback, source file propagation, and unchanged markdown rule fallback.

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Summary by cubic

Parse markdown files referenced in config.yaml prompts blocks as prompts instead of rules, so referenced prompts are no longer dropped. Non-prompts markdown fallbacks still parse as rules.

• Bug Fixes
  • Unroll markdown prompt file blocks into prompts by passing a section hint through unroll.ts.
  • Added parseMarkdownPrompt and exported from packages/config-yaml/src/markdown/index.ts to keep name, description, body, and sourceFile.
  • Tests in packages/config-yaml/src/load/unroll.test.ts cover prompt parsing, filename fallback, source propagation, and unchanged rule fallback.

^{Written for commit ca4e36a. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 4 files

_{Re-trigger cubic}