$ca-init — first-run scaffold

Stand up the root-level .codearbiter/ project-state store that opts a repo into arbiter management. This is the v2 replacement for vendoring/init-vendor: no symlinks, no shims, no dual root. It writes the activation flag and the empty state files, then hands off to the populator.

.codearbiter/CONTEXT.md frontmatter arbiter: enabled is the single activation flag — it gates the SessionStart persona injection. The scaffolded CONTEXT.md is a stub (no initialization sentinel), so after scaffolding the project still needs populating before normal operation.

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Explicit population strategies

<!-- command-mode:--greenfield legacy-route:decompose -->

--greenfield selects the exact skills/ca-decompose/SKILL.md workflow.

<!-- command-mode:--brownfield legacy-route:create-context -->

--brownfield selects the exact skills/ca-create-context/SKILL.md workflow. An initialized refresh is routed through $ca-status drift and the existing context-check owner after an explicit scoped or full selection; --brownfield keeps its initial-population lock.

Brownfield host prerequisites

For repositories with existing source, every scaffold and populator step in the Procedure below is conditional on observing these prerequisites first. This applies to both --brownfield and the default auto-detection route. When qualification is unavailable or unknown, stop here and issue the handoff described below. Do not execute the later Procedure steps or enter brownfield population through the When NOT to use section.

Scaffolding enables governance and may install Git hooks before population. It does not qualify the host for context extraction. Before selecting --brownfield or automatically routing existing source to brownfield population, inspect the installed context-creation containment profile in routines/context-creation/SKILL.md, under that exact heading. The active host needs an observed context-specific child profile with enforced read-only containment and report delivery, plus the existing native context writer and approval support. Ordinary unrestricted collaboration agents on Codex desktop/Windows do not satisfy that requirement. The repository-only Claude preparation fixture is neither a shipped consumer route nor proof of a qualified host.

When these prerequisites are unavailable or unknown, report the missing capability before invoking the scaffolder. Keep a fresh repository unactivated and retain every byte of any existing partial state. Name the loaded package, actual host limitation, selected population route and next missing prerequisite in the handoff; leave unobserved qualification and prior operation identities unknown. Resume on a host only after fresh containment and writer qualification, using the existing interrupted-population recovery procedure. No supported destination is implied by this guidance.

This is a workflow preflight. The low-level scaffolder has no native scout capability attestation input and does not enforce or prove this assessment. Its successful exit, --check inventory or enabled stub never establishes population readiness. Do not fabricate a profile, receipt, context document or initialization sentinel to pass the later gates.

The two flags are mutually exclusive and neither may combine with --check. --stage N may accompany one only while .codearbiter/CONTEXT.md is absent: after any required brownfield preflight, scaffold at that stage, then enter the selected workflow. When an uninitialized stub already exists, skip the refusing scaffolder and enter the selected workflow directly. An initialized marker or source-shape mismatch retains the selected legacy workflow's BLOCK. Without an explicit strategy, continue with the unchanged auto-detection procedure below only after any required brownfield preflight.

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Procedure

Before opening an active host session in an unfamiliar repository, a trusted external process may inspect an explicit directory with python "${PLUGIN_ROOT}/hooks/init-codearbiter.py" --check --passive --root PATH. This bounded read checks only that directory's .codearbiter/CONTEXT.md activation marker and prints a JSON inventory for Git hooks/exclusions, background Git fetch, update refresh, and inference transport. Every effect is performed: false, with capability unverified and authorization not_established. The root is caller supplied and unverified; no Git command, repository script, network request, global setting edit, or model source read occurs. Sensitive/excluded source paths must be inventoried separately before any model read. If an active host session has already started, this inspection cannot undo its earlier startup effects.

Activation is a separate step under the applicable host, network, repository-write, and inference permissions. The normal scaffold and active SessionStart behavior below remain in force for repositories that already opted in.

1. Run the scaffolder against the repo's git toplevel (resolved by the script):

   python "${PLUGIN_ROOT}/hooks/init-codearbiter.py"
   

   It is idempotent and refuses if .codearbiter/CONTEXT.md already exists — it never overwrites state. Pass --stage N to set the initial maturity value (default 1). Use --check to report state without creating anything.

2. It creates .codearbiter/ with: CONTEXT.md (arbiter: enabled, stage: N, stub body), open-tasks.md, open-questions.md, overrides.log (audit header), and last-checkpoint (0).

3. Then route to the populator — the stub is not yet usable:

   • Source code already exists in the repo → route to $ca-create-context (brownfield: scouts read the codebase and synthesize the full context, writing the initialization sentinel).
   • Greenfield (no meaningful source) → route to $ca-decompose (layered interview).

   The populator is mandatory, not optional: it authors tech-stack.md, coding-standards.md, and security-controls.md (and writes the initialization sentinel). The pipeline gates BLOCK on reading those files — writing-plans and tdd need tech-stack.md, the security gates need security-controls.md — so $ca-feature run on a freshly-scaffolded stub will STOP at pre-flight until the populator has run. session-start surfaces this as NOT INITIALIZED every session.

4. Report what was created and which populator you are routing to.

When NOT to use

• .codearbiter/ already scaffolded → the scaffolder refuses; run $ca-create-context or $ca-decompose to populate, or $ca-status to see state.
• You only want to re-check detection state → run the scaffolder with --check.

Hard gate

MUST NOT hand-author .codearbiter/CONTEXT.md frontmatter — the scaffolder is the sanctioned path so the activation flag and state-file shapes match what the hook parses. MUST NOT mark a stub initialized; only the populator writes the initialization sentinel.