`src/middleware/verify.rs` — `VerifyMiddleware`

Runs your verifier after write-class tools succeed and appends the verdict — “verify-on-write” made automatic.

Key items

• Verifier::verify(ctx, tool_name) -> VerifyResult { passed, diagnostics } — async, boxed like Tool::call; NoopVerifier is the do-nothing default.
• VerifyMiddleware::new(verifier, write_tools) — exact-match names.

Behavior notes

• Matches on the resolved (post-rename) tool name — the same key space as the engine’s health recording.
• Appends "\n\n[verify] passed|failed: <diagnostics>"; never sets is_error — a failed verify on a successful write stays a success; the model reads and decides.
• Skipped entirely on tool errors (the tool’s own is_error preserved).
• Cap interaction: with an outer OutputLimitMiddleware, a verify block on output that already fills the cap is truncated away — size the cap with headroom, or observe the verdict from a middleware registered between cap and verify.
• Registered outside memoize: cache hits are still verified (the cache never holds a verify block).

Deep dive: Middleware.