docs(standards): mirror doc-forge wiki style; mermaid + copyable build prompt

- move templates into src/templates; renumber wiki pages; add app-components page

- embed agentic build prompt as a copyable markdown block; add mermaid diagrams

- build.py writes <name>/mcp; config static bundle -> standards/mcp

- registry reads libraries.json as bytes (committed file was UTF-16LE); normalize to UTF-8

- Dockerfile: drop stale blog copy; per-repo <name>/mcp copies

- drop nested standards/mcp/standards duplicate and empty root mcp/

standards/src/templates/app/domain/item/ports/db.py

@@ -0,0 +1,20 @@
+"""# Summary
+
+Mongo persistence for items: document schema and repository factory.
+"""
+from domain.item.models import Item
+from infra.db.repos.mongo import _repo_factory as mongo_repo_factory
+from mongo_ops import BaseDocument, BaseRepository
+
+
+class ItemDocument(Item, BaseDocument):
+    """Mongo document form of :class:`Item`."""
+
+
+def create_item_repo() -> BaseRepository:
+    """Create the Mongo-backed item repository.
+
+    Returns:
+        BaseRepository: Repository wired to the ``items`` collection.
+    """
+    return mongo_repo_factory("items", ItemDocument)