docs: document internal semantic infrastructure

docs/install/local-workspace-registry.md

@@ -130,8 +130,11 @@ before creating sessions. Git pull/push over SSH remains fully supported and is
 ## Bootstrap, first pull, and diagnostics
 
 Use the repository's canonical `compose.yaml` plus `deploy/compose.local.yaml`; they always start
-the mandatory `frontend` and `core` services. Do not copy or maintain a standalone application
-Compose file. Copy [the bindings env example](examples/workspace-bindings.env.example) into an
+`frontend`, `core`, `qdrant`, `embedding`, and the one-shot `embedding-model-init`. This profile
+is CPU-first. Add `THOTH_ENABLE_EMBEDDING_GPU=1` only on a Linux host that intentionally exposes a
+supported GPU device to Docker. Qdrant is a derived but persistent index, while Ollama keeps a
+local model cache for `qwen3-embedding:0.6b` (`1024` dimensions, cosine distance). Do not copy or
+maintain a standalone application Compose file. Copy [the bindings env example](examples/workspace-bindings.env.example) into an
 untracked operator directory and create a protected operator env file from
 `deploy/env/local.env.example`. It must contain absolute `PI_AUTH_FILE`,
 `THT_SECRETS_FILE`, `THT_WORKSPACE_BINDINGS_ENV_FILE`, and connector `*_SOURCE` paths.
@@ -172,6 +175,10 @@ Use `POST /workspace-registry/pull` to fetch later revisions. Run workspace diag
 required DWH bindings are mounted. Schema-v3 diagnostics probe the internal Qdrant/Ollama
 services through backend config; ordinary diagnostics are read-only.
 
+Schema-v3 is the only operational descriptor format. Schema-v1/v2 descriptors remain
+`migration_required` until an explicit reviewed migration writes schema version 3. One workspace owns one Qdrant collection; schema, Evidence, and Memory records share that collection and remain
+isolated by payload `kind`.
+
 To migrate an existing legacy descriptor, create/clone an empty private remote, set the absolute
 `THT_SOURCE_ROOT`, transform with absolute paths, review the schema-v1 result, explicitly produce
 the reviewed schema-v3 contract, then commit/push. The transformer never imports `${ENV}` values