Conduct stack research and codebase investigation for the target phase, validating dependency versions and threat models to produce a structured `RESEARCH.md` document. @.opencode/references/hm-coordination-contracts.md Outputs generated by this workflow are consumed by: 1. **hm-plan**: Uses `RESEARCH.md` to map dependencies, import patterns, and outline specific task behaviors. 2. **hm-gate**: References tech-stack details to verify implementation compliance. **CRITICAL: Investigation only.** The researcher must not implement code changes or modify configurations. All work must be read-only analysis of the workspace and external documentation. Verify phase number from argument ($ARGUMENTS). Check for existing context and boundaries in `CONTEXT.md` or ROADMAP.md. Validate the target technology stack: - Inspect `package.json` and lockfiles to extract installed versions of required libraries. - Run MCP tools (e.g. `context7`) to resolve library IDs and query canonical documentation. - Flag version mismatches or outdated dependencies. Trace implementation coordinates in the active workspace: - Locate source files, interfaces, and patterns to modify or reuse. - Check for existing tests or mocks that can be extended. - Record relative links of relevant files. Identify security vectors: - Formulate STRIDE threats specific to the component/feature domain. - Map trust boundaries and design mitigation strategies. Draft recommendations for any open questions, architectural alternatives, or risks. Generate `${phase_dir}/${padded_phase}-RESEARCH.md` using the standard `hm-research` template, substituting stack versions, codebase paths, and threat details. Stage and commit the generated `RESEARCH.md` file atomically to git. Record research completion details in `.planning/STATE.md` and commit. - Library versions confirmed against workspace lockfile and MCP. - Codebase paths mapped with relative links. - STRIDE threat model mapped. - `RESEARCH.md` written and committed.