docs: Phase 0 — promote AR-designed product identity (#254)

[scrimshawlife-ctrl]

Authority context

Closes #254.

This is Phase 0 of the AR redesign plan (docs/plans/AR_APP_REDESIGN_PLAN.md). It is pure documentation + agent-context alignment. No Swift behavior change, no freeze lift, no Core boundary change.

What changed

File	Change
docs/SOLO_MVP_SCOPE.md	Product promise rewritten: AR-designed primary surface; audio as supporting channel
WAYKIN_SPEC.md	Product contract updated to AR-designed; movement remains sole gameplay authority
README.md	Hero line + semantic audio pillar wording
docs/design/AR_MVP_FREEZE.md	Version 1.3; explicit note that Phase 0 (#254) does not lift the freeze

Allowed systems

Docs only (binding product language + freeze pointer).

Frozen systems

• All of App/AR/** (freeze remains fully in force)
• WaykinCore
• Movement, Bond, pursuit, event generation, persistence
• Outdoor quality claims

Explicit non-goals

• Any feature work
• Freeze exception
• Continuous walker re-anchor
• New ARWorldCommand cases
• Dropping semantic audio

Validation

• Documentation-only change
• make validate expected green (no code touched)
• After merge: residual “audio-first” language should only appear in historical notes or clearly non-genus contexts

Risk / rollback

Low. Pure docs. Revert the PR if identity language proves confusing.

Device evidence

Not required for this change.

[scrimshawlife-ctrl]

Review checklist (Phase 0 docs only)

• Identity language — SOLO_MVP_SCOPE.md, WAYKIN_SPEC.md, and README hero no longer describe Waykin as audio-first. AR is primary designed surface; audio is supporting; movement remains gameplay authority.
• Freeze integrity — AR_MVP_FREEZE.md v1.3 explicitly states Phase 0 (Phase 0: Promote AR-designed product identity (docs only) #254) does not lift the freeze. No App/AR/** or Core changes in this PR.
• Scope discipline — Diff is documentation only. No Swift, no asset, no test behavior change.
• Residual search — After merge, rg -n -i 'audio-first|audio first' --glob '!**/receipts/**' should return only historical / redesign-plan notes or clearly non-genus wording.
• Validate — make validate still green (docs-only; expected).
• Authority — Closes Phase 0: Promote AR-designed product identity (docs only) #254. Ready to mark non-draft and merge when the above are confirmed.

Low risk. Pure product-law alignment.

[scrimshawlife-ctrl]

Superseded by consolidated suite: https://github.com/Zero-State-LLC/Waykin/pull/1 (and personal branch docs/app-product-suite). Closing draft Phase 0 duplicate.