tablet 58: the tool's answer is given — tool results are sources; markers on word boundaries

The sugya reply came back lo_tov — golden_calf on two sentences the
builder had just read from tool output (the Mishnah's reasons, from the
second scroll; the commit and pod, from its own tools). The gate's
sources were only the user turns' text and document blocks; a
tool_result block and a tool turn — what the model was GIVEN (tablet
49) — were not counted. And "shorashim-675b…" was vital because the
insight markers matched "Rashi" inside it.

- Shape.sources: Anthropic tool_result blocks (string or blocks) inside
  a user turn, and OpenAI role "tool" turns, are sources; the query is
  still the last user turn. gate_test: both shapes.
- zerikah._INSIGHT_MARKERS: \b…\b. test_zerikah: the pod name is not
  Rashi; "Rashi reads" and "The Mishnah records" are; "Rambanovich" and
  "talmudic_engine" are not.
- Tablet 58 in the Broken Tablets.

Elixir 643/0, korban 294/0. Doorpost pin unchanged.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

vav_pipeline/lib/vav_pipeline/gate/shape.ex

@@ -52,9 +52,10 @@ defmodule VavPipeline.Gate.Shape do
   # sources pass the cap — a coding agent's conversation runs to megabytes.
   @max_source_bytes 1_048_576
 
+  # A "tool" turn (OpenAI) is what a tool returned to the model: given, a source (tablet 58).
   defp user_sources(messages, text_fun) do
     messages
-    |> Enum.filter(&(&1["role"] == "user"))
+    |> Enum.filter(&(&1["role"] in ["user", "tool"]))
     |> Enum.with_index(1)
     |> Enum.flat_map(fn {m, i} -> text_fun.(m) |> wrap("user_#{i}") end)
     |> Enum.reverse()
@@ -93,6 +94,11 @@ defmodule VavPipeline.Gate.Shape do
       %{"type" => "text", "text" => t} when is_binary(t) -> [t]
       %{"type" => "document", "source" => %{"type" => "text", "data" => t}} when is_binary(t) -> [t]
       %{"type" => "document", "source" => %{"type" => "content", "content" => inner}} when is_list(inner) -> [text_of_blocks(inner)]
+      # Tablet 58: what a tool returned to the model was GIVEN to it
+      # (tablet 49) — a file it read, a reply from a service, the scroll
+      # it consulted. A claim that rests on it rests on a source.
+      %{"type" => "tool_result", "content" => c} when is_binary(c) -> [c]
+      %{"type" => "tool_result", "content" => inner} when is_list(inner) -> [text_of_blocks(inner)]
       _ -> []
     end)
     |> Enum.join("\n")