feat(agents): ground RPI research integrations across planning workflows

Ground decision-critical evidence gathering across existing planning workflows by integrating `rpi-research` at bounded points. The work covers an architecture review gate, experiment preparation, shared BRD/PRD research receipts and dispositions, and a current-evaluator lookup route for the Data Science evaluation job. Each parent workflow retains its lifecycle, decisions, and artifact authority.

## Acceptance Criteria

- [ ] System Architecture Reviewer activates `rpi-research` only for a demonstrated current-service, framework, cost, licensing, compatibility, or prior-art gap and stops dependent recommendations when Research is blocked.
- [ ] Experiment Designer uses Research as preparation before hypothesis finalization and never treats it as experiment validation or a substitute for collaborative execution.
- [ ] `requirements-author` defines one pointer-based Research receipt and finding-disposition contract consumed by BRD Builder and PRD Builder, while `BRD_TO_PRD_HANDOFF_V1` remains unchanged.
- [ ] BRD and PRD state and document guidance preserve Research provenance, evidence status, affected targets, dispositions, and unresolved items without transferring requirement authority.
- [ ] The Data Science and Engineering Coach uses bounded Research for live evaluator-catalog facts only inside the confirmed evaluation job and preserves job identity and metric-selection ownership.
- [ ] Vally adds between five and ten isolated agent stimuli, with at least one and at most two per changed agent, plus no more than three owning-skill stimuli; removes none; separates success-path behavior from blocked or unavailable Research handling when needed; and tests activation thresholds, bounded briefs, authority boundaries, and receipt or disposition behavior.
- [ ] The generated agent-behavior eval, plugin manifest, extension projection, and generated reference documentation are synchronized from canonical sources.
- [ ] Local static validation passes, and hosted Vally execution and moderation complete through the owning CI lanes.

## Definition of Done

- [ ] Changed agents, skills, references, templates, and eval sources follow repository authoring and licensing conventions.
- [ ] No workflow treats Research as an architecture decision, experiment result, approved requirement, user research finding, feasibility verdict, or metric-selection decision.
- [ ] Validation evidence and any CI-owned pending results are reported accurately.