ci: use zerto-docs's load-balanced Ollama GPU pool on the Gitea host

Match the OLLAMA_URLS pattern from zerto-docs-rag so every docs MCP
build fans out across the same two GPU-pinned Ollama containers on
192.168.0.2 (:11435 Titan X, :11436 1080 Ti). The host's primary
Ollama on :11434 is left alone for OpenWebUI.

rag.embeddings now reads OLLAMA_URLS (plural CSV) preferentially with
fallback to OLLAMA_URL, defaulting to http://192.168.0.2:11434 — same
shape as zerto's embeddings.py. The OllamaEmbeddings class already
round-robins per batch, so both GPUs run in parallel during the
chroma rebuild.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

rag/embeddings.py

@@ -3,8 +3,15 @@
 Swappable: implement the same `embedding_function()` interface returning
 a Chroma `EmbeddingFunction` and the rest of the pipeline doesn't care.
 
-Defaults (override via env):
-  OLLAMA_URL    one or more comma-separated URLs (load-balanced)
+Env-configurable (matches the zerto-docs-rag pattern so the same Gitea
+runner + GPU-pinned Ollama containers can serve every docs MCP build):
+
+  OLLAMA_URLS   comma-separated list, load-balanced round-robin per batch.
+                Preferred — set in the CI workflow to fan out across two
+                GPU-pinned Ollama containers on the Gitea host.
+  OLLAMA_URL    single endpoint, fallback when OLLAMA_URLS is unset.
+                Default http://192.168.0.2:11434 (the host where the GPUs
+                live in Justin's lab).
   EMBED_MODEL   model name; default 'nomic-embed-text'
   EMBED_DIM     expected embedding dim; default 768 (nomic-embed-text)
 """
@@ -19,8 +26,18 @@ from chromadb import EmbeddingFunction, Documents, Embeddings
 
 log = logging.getLogger(__name__)
 
-OLLAMA_URLS = [u.strip() for u in os.environ.get("OLLAMA_URL",
-               "http://localhost:11434").split(",") if u.strip()]
+DEFAULT_OLLAMA_URL = "http://192.168.0.2:11434"
+
+
+def _resolve_urls() -> list[str]:
+    raw = os.environ.get("OLLAMA_URLS", "").strip()
+    if raw:
+        return [u.strip().rstrip("/") for u in raw.split(",") if u.strip()]
+    single = os.environ.get("OLLAMA_URL", DEFAULT_OLLAMA_URL).strip().rstrip("/")
+    return [single]
+
+
+OLLAMA_URLS = _resolve_urls()
 EMBED_MODEL = os.environ.get("EMBED_MODEL", "nomic-embed-text")
 EMBED_DIM = int(os.environ.get("EMBED_DIM", "768"))