read_doc: resolver docs por ACAI_PROJECT_DIR + knowledge load idempotente

- mcp-server _docsReader.js: resolveDocsDir → ACAI_DOCS_DIR /
  $ACAI_PROJECT_DIR/docs / /app/docs. Arregla DOC_NOT_FOUND en VSCode
  (HTTP MCP) y local; el .mcp.json ya inyecta ACAI_PROJECT_DIR
- routes.py: /knowledge/load idempotente — salta embeddings si el hash
  de contenido no cambió (clave Redis kbhash), para dispararlo libremente
  desde el botón de scaffold sin re-embeber

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/api/routes.py

@@ -786,25 +786,62 @@ async def _load_knowledge_from_dir(docs_path: str = "docs") -> dict[str, Any]:
 
         docs_data.append((doc_id, title, content, summary, tags, priority, load_when))
 
-    # Generate embeddings in batch (solo si hay credencial de embeddings; sin
-    # ella la llamada daria 401 — se omite limpiamente).
+    # Hash de contenido por doc — base del skip idempotente de embeddings.
+    import hashlib
+
+    def _embed_text(title, summary, content):
+        return f"{title}\n{summary}\n{content[:2000]}"
+
+    def _doc_hash(title, summary, content):
+        return hashlib.md5(_embed_text(title, summary, content).encode("utf-8")).hexdigest()
+
+    new_hashes = [_doc_hash(t, s, c) for _, t, c, s, _, _, _ in docs_data]
+
+    # Generate embeddings SOLO para docs nuevos o cuyo contenido cambió (skip
+    # idempotente): si el hash coincide con el guardado y ya existe el embedding
+    # en Redis, se reutiliza y NO se vuelve a llamar a la API. Esto permite que
+    # /knowledge/load se dispare libremente (botón de scaffold, etc.) sin re-embeber.
     embeddings: list[Any] = [None] * len(docs_data)
+    already_embedded = [False] * len(docs_data)
     has_embeddings = False
     if settings.embeddings_enabled:
-        from ..memory.embeddings import EmbeddingService
-        embed_service = EmbeddingService()
-        embed_texts = [
-            f"{title}\n{summary}\n{content[:2000]}"
-            for _, title, content, summary, _, _, _ in docs_data
-        ]
-        try:
-            embeddings = await embed_service.embed_batch(embed_texts)
+        to_embed = []  # indices que hay que (re)embeber
+        for i, (doc_id, title, content, summary, _, _, _) in enumerate(docs_data):
+            try:
+                prev = await memory._r.get(memory._key("kbhash", "knowledge", doc_id))
+                if isinstance(prev, bytes):
+                    prev = prev.decode("utf-8")
+                has_embed = await memory._r.exists(memory._key("embeddings", "knowledge", doc_id))
+            except Exception:
+                prev, has_embed = None, 0
+            if prev == new_hashes[i] and has_embed:
+                already_embedded[i] = True  # sin cambios → reutiliza el embedding existente
+            else:
+                to_embed.append(i)
+
+        if to_embed:
+            from ..memory.embeddings import EmbeddingService
+            embed_service = EmbeddingService()
+            embed_texts = [
+                _embed_text(docs_data[i][1], docs_data[i][3], docs_data[i][2])
+                for i in to_embed
+            ]
+            try:
+                fresh = await embed_service.embed_batch(embed_texts)
+                for j, i in enumerate(to_embed):
+                    embeddings[i] = fresh[j]
+                has_embeddings = True
+                logger.info(
+                    "Generated %d embeddings (%d sin cambios, omitidos)",
+                    len(to_embed), len(docs_data) - len(to_embed),
+                )
+            except Exception as e:
+                logger.warning("Failed to generate embeddings: %s — loading without semantic search", e)
+                embeddings = [None] * len(docs_data)
+                has_embeddings = False
+        else:
             has_embeddings = True
-            logger.info("Generated %d embeddings for knowledge base", len(embeddings))
-        except Exception as e:
-            logger.warning("Failed to generate embeddings: %s — loading without semantic search", e)
-            embeddings = [None] * len(docs_data)
-            has_embeddings = False
+            logger.info("Knowledge sin cambios — no se regeneraron embeddings (%d docs)", len(docs_data))
     else:
         logger.info("Embeddings disabled (no AGENTIC_EMBEDDINGS_API_KEY) — KB loaded without semantic search")
 
@@ -817,9 +854,10 @@ async def _load_knowledge_from_dir(docs_path: str = "docs") -> dict[str, Any]:
     for existing in existing_docs:
         if existing.memory_id not in current_ids:
             await memory.delete_document(existing.memory_id, namespace="knowledge")
-            # Borra también el embedding asociado
+            # Borra también el embedding asociado y el hash de contenido
             embed_key = memory._key("embeddings", "knowledge", existing.memory_id)
             await memory._r.delete(embed_key)
+            await memory._r.delete(memory._key("kbhash", "knowledge", existing.memory_id))
             removed.append(existing.memory_id)
     if removed:
         logger.info("Removed %d stale knowledge docs: %s", len(removed), removed)
@@ -842,6 +880,11 @@ async def _load_knowledge_from_dir(docs_path: str = "docs") -> dict[str, Any]:
 
         if embeddings[i] is not None:
             await memory.store_embedding(doc_id, embeddings[i], namespace="knowledge")
+            # Guarda el hash de contenido para el skip idempotente del próximo load
+            try:
+                await memory._r.set(memory._key("kbhash", "knowledge", doc_id), new_hashes[i])
+            except Exception:
+                pass
 
         loaded.append({
             "id": doc_id,
@@ -850,7 +893,7 @@ async def _load_knowledge_from_dir(docs_path: str = "docs") -> dict[str, Any]:
             "tags": tags[:5],
             "priority": priority,
             "load_when": load_when,
-            "embedded": embeddings[i] is not None,
+            "embedded": embeddings[i] is not None or already_embedded[i],
         })
 
     logger.info("Loaded %d knowledge documents from %s (embeddings: %s)", len(loaded), docs_dir, has_embeddings)