chat-tool-search journey fails when Haiku guesses a tool name before searching #202

Found while working #195.

Problem

The devbox verify run for eve#201 (head f9a9efe, 2026-10-06 05:15 UTC) failed chat-tool-search: the first tool step is "call_tool", not tool_search (steps: call_tool, tool_search, call_tool). Haiku first called call_tool with a guessed name (relay-tides), got unknown tool "relay-tides", then ran tool_search, loaded tides_lookup and answered correctly with the tide code. The same run passed 32 other journeys. eve#201 changes no chat, tool or relay-tools code.

Root cause

The journey requires the model's first tool step to be tool_search. Haiku sometimes guesses a tool name from the skill list first. The answer is still right, and the order is the model's choice, not eve's or relay's.

Fix

To be decided: either the journey accepts a failed call_tool on an unknown name before tool_search (that still proves the search path ran and produced the answer), or the tool-search prompt/skill text steers the model to search first. Changing the journey's assertion is a harness-decision change, so it needs the owner (gate 2).

Decisions made for the owner

• The journey treats a step as a guessed name only when its result parses as JSON whose error starts with unknown tool " (relay's exact refusal). A not loaded refusal or any other step before tool_search still fails, and so does free text that merely mentions an unknown tool.
• Any number of leading guesses is accepted, not just one. The owner's approval names no limit, and tool_search must still follow.
• The detail checks (call_tool names tides_lookup, direct step shows the nonce) read only steps after tool_search, so a guess can't satisfy them.
• Red on main uses a stand-in commit, 3b70e03. It extracts main's order check into searchStep unchanged, because the order rule had no unit-reachable door on main.

Contract

• searchStep(steps) -> { index } | { error } and detailProblem(steps, searchIndex, nonce) -> string | null, both exported from devboxverify/journeys-tool-search.js. steps is [{ name, input, output }] as toolSteps() reads the thread.
• Ownership: devboxverify/journeys-tool-search.js, devboxverify/README.md, test/unit/devboxverify-tool-search.test.js.
• Waits: none new. The unit tests are synchronous, and the journey's polls are unchanged.