The closest existing engine to shard-wiki's own design: DB-canonical
(Postgres/MySQL/SQLite) but with a pluggable storage-module abstraction
that bidirectionally syncs clean Markdown (+ YAML frontmatter) to Git
(also FS/S3/Azure), each provider acting as backup or source of truth.
Two big findings: (1) the storage-module interface is concrete
adapter-contract prior art alongside Foswiki::Store, and the closer one
(medium = Markdown in Git); (2) the engine-maintained bidirectional Git
mirror is the ideal file-store attach (clean MD + git history) and, being
bidirectional, makes git commit a write path (overlay/patch as a commit,
no API). Also GraphQL API (introspection = capability discovery;
selective fields = efficient projection) and authn-delegated auth modules
+ path-based rule ACL. Added UC-68 (engine-maintained bidirectional Git
mirror, write-by-commit), UC-69 (typed/introspectable API for schema
discovery + selective projection); enriched UC-06/36/38/40/42/57. Catalog
now 69 UCs. Architecture for SHARD-WP-0002 T11/T14: storage-module
abstraction as 2nd adapter-contract prior art, engine-maintained Git
mirror as attach+write surface, GraphQL introspection for capability
discovery.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>