feat: staged AQE initializer #335

Why

aqe init is not idempotent (agentic-qe#778) and writes .mcp.json in personal mode (design: Upstream initializers are staged).

In scope

Stage aqe init the same way as Ruflo; register AQE at local scope in personal mode; release legacy AQE pin receipts only: the pin is retired by #441 (ADR-0062), so no pin is written or migrated into project state.

Out of scope

Embeddings (#352).

Acceptance criteria

• Re-running init leaves AQE files unchanged
• Personal mode does not write .mcp.json

Dependencies

Blocked by: #334, #441

Blocks: #347, #352, #385

Plan

• Release: 4.0.0-beta.1
• Size: size:M · Workstream: ws:project-scope
• Epic: feat: project-scope P1, project layout and ak init (epic) #296
• Card: P1-06 in the card inventory
• Sources: Design (docs(plans): project-scoped management design and its prerequisites #289) Upstream initializers; Supersession ledger (docs(plans): v4 GA master plan, supersession ledger and v5 registers #290) D-6, B5-D1

Verification

• node scripts/run-tests.mjs focus (new staging tests)