S1: the three-mode surface — plan · develop · research, auto implied (spec-20260907-011500 D1)

[aarontrowbridge]

Important

Problem — Four named modes (plan, build, autodev, autoresearch), stock-alphabetical picker, no posture story. Aaron's ruling: three modes, auto implied.
Approach — Design-of-record: vault specs/spec-20260907-011500-three-modes-subagent-routing.md (rev 2, two-lens APPROVED) — D1. Rename autodev→develop, autoresearch→research with READ-RESOLVE aliases (never migrate-on-write; append-only artifacts keep old ids forever, resolved at read; tooling joins support both ids permanently). build remains a valid explicit id everywhere (default_agent, spawn params, CLI args) — it exits the PICKER, not the vocabulary. Alias covers all reference surfaces (config keys, amico_session agent param, CLI args, prompt prose). Alias removal rides the next contract-version bump (freeze-validator-legal exit). Picker order: plan → develop → research (amends fork PR #305's order). The mode registry borrows the freeze validator as a lint — a premium-staging regression must never block a public rename (asserted by test).

Acceptance Criteria (spec S1)

• The picker lists exactly plan · develop · research; the default posture is reachable and marked implied
• autodev/autoresearch resolve as aliases everywhere; rename sweep covers mode blocks, role cards, director cards' self-references, skill/mode vocabulary
• The registry passes the freeze validator (as lint); the public-rename-independence test lands