Refactor documentation and diagrams for web/pipeline. (#272)

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com> for assistance with diagram creation and documentation prose updates.

docs/web/diagrams/database-schema.md

@@ -0,0 +1,40 @@
+# Database Schema
+
+Five diagrams, one per schema category — mirrors the `identity` / `media` /
+`location` / `brewery` / `beer` schema split. Every table also has a
+`RowVersion ROWVERSION` column (optimistic concurrency), omitted below for
+brevity. Tables marked `(*)` have no repository/feature slice yet.
+
+Boxes with no attribute list (e.g. `Photo` in the identity diagram) are owned by
+a different schema and shown only to keep the relationship visible; see the
+diagram named after that schema for its full definition.
+
+## Identity (`identity`)
+
+```mermaid
+--8<-- "web/diagrams/database-schema/identity.mmd"
+```
+
+## Media (`media`)
+
+```mermaid
+--8<-- "web/diagrams/database-schema/media.mmd"
+```
+
+## Location (`location`)
+
+```mermaid
+--8<-- "web/diagrams/database-schema/location.mmd"
+```
+
+## Brewery (`brewery`)
+
+```mermaid
+--8<-- "web/diagrams/database-schema/brewery.mmd"
+```
+
+## Beer (`beer`)
+
+```mermaid
+--8<-- "web/diagrams/database-schema/beer.mmd"
+```