Replace artifact_type with domain on Mists

Replace artifact_type with domain on Mists

Background

Mists are quick one-off artifacts — the Muse equivalent of a GitHub Gist. They map naturally to Muse domains: a Python snippet is a code mist, a MIDI phrase is a midi mist, a future audio clip would be a stems mist.

The current artifact_type field predates this domain model and has accumulated conflicting classifications:

The language field already carries the specificity that the subtypes were trying to capture. artifact_type is a redundant and confusing layer.

Goal

Replace artifact_type with domain everywhere: DB column, API wire format, CLI flags, and UI. Valid domain values are code, midi, and stems. All text-based subtypes collapse to domain=code with language retaining the specificity (e.g. markdown, python, json, yaml).

Before:

{ "artifactType": "schema", "language": "" }
{ "artifactType": "prose",  "language": "markdown" }
{ "artifactType": "code",   "language": "python" }

After:

{ "domain": "code", "language": "json" }
{ "domain": "code", "language": "markdown" }
{ "domain": "code", "language": "python" }

Phases

Phase 1 — Database migration

Must be fully green before Phase 2 begins.

Add domain column to musehub_mists and backfill from artifact_type + language. Then drop artifact_type.

Backfill rules:

Deliverables:

• 0071_mist_domain.py — alembic migration (MD_01, MD_02, MD_03)
  • upgrade(): add domain NOT NULL with default code, backfill from table, drop artifact_type
  • downgrade(): restore artifact_type from domain, drop domain

Tests (run against a real DB, no mocks — tests/test_migration_0071.py):

• MD_01 — all existing artifact_type values map to the correct domain after upgrade
• MD_02 — language is backfilled correctly for schema, abi, config, dataset, prose
• MD_03 — downgrade restores artifact_type; no rows lost

Phase 2 — Server models + API

Depends on Phase 1. Must be fully green before Phase 3 or Phase 4 begins.

Replace artifact_type with domain in the server-side models and all API endpoints.

Deliverables:

• musehub/db/musehub_repo_models.py — MusehubMist.domain: str replaces artifact_type
• musehub/models/mists.py — MistResponse, MistListEntry, MistForkResponse use domain; MistCreateRequest accepts domain, rejects unknown values with 422; MistUpdateRequest accepts optional domain
• musehub/services/musehub_mists.py — all references to artifact_type replaced with domain
• musehub/services/musehub_proposals.py — _DOMAIN_WEIGHTS keys use actual domain values; domain heat dict updated
• musehub/services/spectral_sigil.py — DOMAIN_COLORS keyed on code, midi, stems
• Wire format: domain in camelCase is still domain (no rename needed)

Tests (tests/test_mist_routes.py):

• MD_04 — POST /api/mists with domain=code returns 201 with domain in response
• MD_05 — POST /api/mists with domain=midi returns 201
• MD_06 — POST /api/mists with unknown domain returns 422
• MD_07 — GET /api/mists/{id} returns domain, no artifactType key
• MD_08 — GET /api/{owner}/mists list entries contain domain

Phase 3 — CLI

Depends on Phase 2. Must be fully green before Phase 5 begins.

Replace --type with --domain on muse hub mist create. Update all --json output keys.

Deliverables:

• muse/cli/commands/hub/mists.py — --domain flag (values: code, midi, stems; default code); remove --type
• All --json output: domain key replaces artifactType / artifact_type

Tests (tests/test_hub_mist_cli.py):

• MD_09 — muse hub mist create --domain code succeeds and --json output contains domain: "code"
• MD_10 — muse hub mist create --domain midi succeeds
• MD_11 — --type flag no longer exists (passing it raises an error)

Phase 4 — UI + templates

Depends on Phase 2. Must be fully green before Phase 5 begins.

Update all template and route logic that reads artifact_type / prism_lang mapping.

Deliverables:

• musehub/api/routes/musehub/ui_mists.py — _prism_map keyed on domain + language; _TYPE_COLORS → _DOMAIN_COLORS; display_artifact_type → display_domain; md_html branch still driven by language == "markdown"
• musehub/templates/musehub/pages/mist_detail.html — badge shows domain + language (e.g. code · markdown, midi)
• musehub/templates/musehub/pages/mist_list.html, mist_explore.html, mist_embed.html — same badge update
• musehub/templates/musehub/fragments/mist_rows.html — same

Tests (visual — no test ID; verify manually on staging):

• MD_12 — markdown mist shows code · markdown badge and renders as HTML
• MD_13 — Python mist shows code · python badge and syntax-highlighted source
• MD_14 — MIDI mist shows midi badge and download placeholder

Phase 5 — Integration + cleanup

Depends on Phases 3 and 4.

End-to-end round-trip and removal of all remaining artifact_type references.

Deliverables:

• muse content-grep "artifact_type" returns zero results across both repos
• muse content-grep "artifactType" returns zero results (excluding this issue body)
• Integration test: create mist via CLI → read via API → verify detail page renders correctly (MD_15)

Tests:

• MD_15 — full round-trip: muse hub mist create --domain code --language markdown → GET /api/mists/{id} returns domain=code, language=markdown → detail page renders HTML

Acceptance Criteria

• No artifact_type or artifactType anywhere in code, tests, templates, or docs (except this issue body and migration downgrade path)
• All existing mists have domain set correctly after migration
• domain is one of code, midi, stems — no other values accepted
• language continues to drive syntax highlighting and markdown rendering
• The "prose" badge is gone forever

Out of Scope

• Adding stems domain rendering (MIDI is the only non-code domain with active rendering today)
• API versioning / backwards compatibility for external callers
• Mist search or filtering by domain (follow-on feature)