Rough Idea: Add roo-cli as a Provider to Ralph Orchestrator

What

Add roo (Roo Code CLI) as a new backend provider in ralph-orchestrator, enabling ralph run -b roo and ralph plan -b roo.

Context

• Roo Code CLI (roo, v0.1.15+) is an AI coding assistant that supports multiple LLM providers (Anthropic, OpenAI, AWS Bedrock, OpenRouter)
• Roo CLI source is at /Users/skven/workplace/Roo-Code/apps/cli/
• Install: cd /Users/skven/workplace/Roo-Code/src && pnpm run bundle && cd /Users/skven/workplace/Roo-Code && pnpm --filter @roo-code/cli build && npm install -g ./apps/cli
• Binary: roo (installed globally via npm)

Key Decisions (already researched and validated)

1. Text mode only — Use roo --print --ephemeral "prompt" (plain text output, like kiro). Stream-JSON deferred to later.
2. Always use --prompt-file — Roo natively supports --prompt-file <path>. All prompts use this (one code path, no size threshold).
3. --ephemeral included — Fixed in roo v0.1.15+ to work with Bedrock. Clean disk state per iteration.
4. Tool auto-approval is default — No --trust-all-tools flag needed (unlike kiro).
5. Interactive mode: roo "prompt" for ralph plan.
6. Auto-detect last in priority: ["claude", "kiro", ..., "pi", "roo"].
7. Roo always exits code 0 — Even on API errors. Ralph relies on LOOP_COMPLETE/event presence.
8. Event tags work — Roo emits <event topic="build.done"> and LOOP_COMPLETE when Ralph-style system instructions are provided.

Working Test Commands

# Headless (text mode)
roo --provider bedrock --aws-profile roo-bedrock --aws-region us-east-1 --model anthropic.claude-sonnet-4-6 --max-tokens 64000 --print "Say hello"

# With prompt file
echo "Your prompt" > /tmp/prompt.txt
roo --provider bedrock --aws-profile roo-bedrock --aws-region us-east-1 --model anthropic.claude-sonnet-4-6 --max-tokens 64000 --print --prompt-file /tmp/prompt.txt

# Stream JSON (for future reference)
roo --provider bedrock --aws-profile roo-bedrock --aws-region us-east-1 --model anthropic.claude-sonnet-4-6 --max-tokens 64000 --print --output-format stream-json "Say hello"

Files to Modify

1. crates/ralph-adapters/src/cli_backend.rs — Add roo(), roo_interactive(), registration in from_config, from_name, for_interactive_prompt
2. crates/ralph-adapters/src/auto_detect.rs — Add "roo" to DEFAULT_PRIORITY, update NoBackendError
3. crates/ralph-adapters/src/lib.rs — Update doc comment
4. presets/minimal/roo.yml — New preset (mirror kiro.yml, change backend to "roo")

Design & Research (already completed)

Full PDD artifacts at .agents/planning/2026-03-03-roo-cli-provider/:

• design/detailed-design.md — Complete design document
• implementation/plan.md — 7-step implementation plan with checklist
• research/assumption-validation.md — All 9 assumptions verified with live tests
• research/roo-cli-interface.md — Complete CLI flag documentation