Lays the additive foundation for hosting N projects per deployment, with
today's single corpus as the N=1 case. No behavior change: the app runs
exactly as before, single project, with the spine underneath.
- migration 025: `projects` + `project_members` tables; seed the `default`
project (visibility=public, preserving open-by-default); thread
`project_id NOT NULL DEFAULT 'default'` onto all 19 slug-bearing tables,
backfilling existing rows. Additive — no table rebuilds; the slug-keyed
uniqueness/PK rework is enumerated in the migration header and deferred to
the slice that activates project #2.
- app/projects.py: §22.13 startup backfill of the default project's
content_repo from META_REPO (idempotent — never clobbers a value the
future registry mirror sets).
- config: REGISTRY_REPO wired (optional through M1; consumed by the M3
mirror), documented in .env.example as META_REPO's successor.
- tests: 6 vertical assertions on the spine (seed, backfill, column shape,
role CHECK, idempotency, config). Full suite 381 passed.
- docs: align Part C M1/M3 boundaries with the landed code (registry mirror
+ redirect move to M3).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Ben Stull