refactor: remove search_surfsense_docs tool and related references

- Deleted the `search_surfsense_docs` tool and its associated files, streamlining the agent's toolset.
- Updated various components and prompts to remove references to the now-removed tool, ensuring consistency across the codebase.
- Adjusted documentation to direct users to the SurfSense documentation link for product-related queries instead.

surfsense_backend/alembic/versions/146_drop_surfsense_docs_tables.py

@@ -0,0 +1,129 @@
+"""Drop Surfsense docs tables (feature removed end to end)
+
+Revision ID: 146
+Revises: 145
+Create Date: 2026-05-28
+
+Removes the SurfSense product-documentation feature: the
+``surfsense_docs_documents`` and ``surfsense_docs_chunks`` tables (created
+in revision 60) and the GIN trigram index on the title column (added in
+revision 67). The docs were seeded at startup from local MDX files, so no
+user data is lost. Downgrade recreates the tables and indexes.
+"""
+
+from collections.abc import Sequence
+
+from alembic import op
+from app.config import config
+
+# revision identifiers, used by Alembic.
+revision: str = "146"
+down_revision: str | None = "145"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+# Embedding dimension is required to recreate the vector columns on downgrade.
+EMBEDDING_DIM = config.embedding_model_instance.dimension
+
+
+def upgrade() -> None:
+    """Drop surfsense docs tables and all their indexes."""
+    # Trigram index from revision 67
+    op.execute("DROP INDEX IF EXISTS idx_surfsense_docs_title_trgm")
+
+    # Full-text search indexes
+    op.execute("DROP INDEX IF EXISTS surfsense_docs_chunks_search_index")
+    op.execute("DROP INDEX IF EXISTS surfsense_docs_documents_search_index")
+
+    # Vector indexes
+    op.execute("DROP INDEX IF EXISTS surfsense_docs_chunks_vector_index")
+    op.execute("DROP INDEX IF EXISTS surfsense_docs_documents_vector_index")
+
+    # B-tree indexes
+    op.execute("DROP INDEX IF EXISTS ix_surfsense_docs_chunks_document_id")
+    op.execute("DROP INDEX IF EXISTS ix_surfsense_docs_documents_updated_at")
+    op.execute("DROP INDEX IF EXISTS ix_surfsense_docs_documents_content_hash")
+    op.execute("DROP INDEX IF EXISTS ix_surfsense_docs_documents_source")
+
+    # Tables (chunks first due to FK)
+    op.execute("DROP TABLE IF EXISTS surfsense_docs_chunks")
+    op.execute("DROP TABLE IF EXISTS surfsense_docs_documents")
+
+
+def downgrade() -> None:
+    """Recreate surfsense docs tables and indexes (reverses revisions 60 + 67)."""
+    op.execute(
+        f"""
+        CREATE TABLE IF NOT EXISTS surfsense_docs_documents (
+            id SERIAL PRIMARY KEY,
+            created_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT NOW(),
+            source VARCHAR NOT NULL UNIQUE,
+            title VARCHAR NOT NULL,
+            content TEXT NOT NULL,
+            content_hash VARCHAR NOT NULL,
+            embedding vector({EMBEDDING_DIM}),
+            updated_at TIMESTAMP WITH TIME ZONE
+        );
+        """
+    )
+    op.execute(
+        f"""
+        CREATE TABLE IF NOT EXISTS surfsense_docs_chunks (
+            id SERIAL PRIMARY KEY,
+            created_at TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT NOW(),
+            content TEXT NOT NULL,
+            embedding vector({EMBEDDING_DIM}),
+            document_id INTEGER NOT NULL REFERENCES surfsense_docs_documents(id) ON DELETE CASCADE
+        );
+        """
+    )
+
+    # B-tree indexes
+    op.execute(
+        "CREATE INDEX IF NOT EXISTS ix_surfsense_docs_documents_source ON surfsense_docs_documents(source)"
+    )
+    op.execute(
+        "CREATE INDEX IF NOT EXISTS ix_surfsense_docs_documents_content_hash ON surfsense_docs_documents(content_hash)"
+    )
+    op.execute(
+        "CREATE INDEX IF NOT EXISTS ix_surfsense_docs_documents_updated_at ON surfsense_docs_documents(updated_at)"
+    )
+    op.execute(
+        "CREATE INDEX IF NOT EXISTS ix_surfsense_docs_chunks_document_id ON surfsense_docs_chunks(document_id)"
+    )
+
+    # Vector indexes
+    op.execute(
+        """
+        CREATE INDEX IF NOT EXISTS surfsense_docs_documents_vector_index
+        ON surfsense_docs_documents USING hnsw (embedding public.vector_cosine_ops);
+        """
+    )
+    op.execute(
+        """
+        CREATE INDEX IF NOT EXISTS surfsense_docs_chunks_vector_index
+        ON surfsense_docs_chunks USING hnsw (embedding public.vector_cosine_ops);
+        """
+    )
+
+    # Full-text search indexes
+    op.execute(
+        """
+        CREATE INDEX IF NOT EXISTS surfsense_docs_documents_search_index
+        ON surfsense_docs_documents USING gin (to_tsvector('english', content));
+        """
+    )
+    op.execute(
+        """
+        CREATE INDEX IF NOT EXISTS surfsense_docs_chunks_search_index
+        ON surfsense_docs_chunks USING gin (to_tsvector('english', content));
+        """
+    )
+
+    # Trigram index from revision 67
+    op.execute(
+        """
+        CREATE INDEX IF NOT EXISTS idx_surfsense_docs_title_trgm
+        ON surfsense_docs_documents USING gin (title gin_trgm_ops);
+        """
+    )