1. Most turns: reading drive_to (2116-2590) and its callees in pieces to design the host trait. The draft was a schematic impl Project with direct calls, so I rebuilt it by hand as a free function with host calls. Before compaction I also spent turns confirming std contracts (fs::metadata, fs::Path, env::var) and how a refusal is downcast (Raised::inner).
2. Looked up that the brief could have handed me:
   • How a thrown refusal reaches Rust: Box<dyn Error> → downcast_ref::<Raised>().inner(). Manifests::error only shows the typed Thrown channel.
   • Which original errors were refuse! and which plain anyhow!. This decides whether Refused(String) alone is enough; I found it is not.
   • The signatures of run_fast::compile, the Cargo fields, run_directly and toolchain_can_build_for, and who else calls it.
   • The lowering trap: "".clone() is refused, "" gives ref String in a closure, and closures cannot declare a return type.
   • That toolchain_can_build_for already held the exact text to move.
3. Checks: the #1060 guard build from HEAD (useful), three lower-std rounds (useful, each found a refusal), two cargo check runs (useful: the second found the defect), and one small probe that confirmed it. Nothing was wasted, because the defect stopped the run before the full build and tests. In hindsight, a probe of the tuple-in-return match shape before writing 500 lines would have found the defect in one turn.
4. One change: a short list in the brief of the shapes the move will use that have no existing pattern in tools/*.nika, here return match with tuple arms holding T?. builder.md would then require one probe program per shape before writing the file. The defect would have stopped the brief at turn 5 instead of after the whole move was written.

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