flow-next-impl-review

# Implementation Review Mode **Workflow is backend-split. Read [workflow-common.md](workflow-common.md) for Phase 0 (backend detection + philosophy + trivial-diff triage + phase-ordering matrix + cross-backend deep/validator/walkthrough phases), then read ONLY the file matching your active backend:** - `BACKEND=codex` → [workflow-codex.md](workflow-codex.md) - `BACKEND=copilot` → [workflow-copilot.md](workflow-copilot.md) - `BACKEND=rp` → [workflow-rp.md](workflow-rp.md) Do not load the other two — only the active backend's file is needed. Conduct a John Carmack-level review of implementation changes on the current branch. **Role**: Code Review Coordinator (NOT the reviewer) **Backends**: RepoPrompt (rp), Codex CLI (codex), or GitHub Copilot CLI (copilot) ## Preamble **CRITICAL: flowctl is BUNDLED — NOT installed globally.** `which flowctl` will fail (expected). Define once; subsequent blocks (here and in `workflow-*.md`) use `$FLOWCTL`: ```bash FLOWCTL="${DROID_PLUGIN_ROOT:-${CLAUDE_PLUGIN_ROOT}}/scripts/flowctl" ``` ## Backend Selection **Priority** (first match wins): 1. `--review=rp|codex|copilot|export|none` argument 2. `FLOW_REVIEW_BACKEND` env var — bare backend (`rp`, `codex`, `copilot`, `none`) OR spec form (`codex:gpt-5.4:xhigh`, `copilot:claude-opus-4.5`) 3. `.flow/config.json` → `review.backend` (same bare / spec forms) 4. **Error** - no auto-detection ### Parse from arguments first Check $ARGUMENTS for: - `--review=rp` or `--review rp` → use rp - `--r...