loom-dead-code-check

# Dead Code Detection ## Overview Dead code — written but never called, imported, or used — is a direct signal of incomplete integration: a function nothing calls means the feature isn't wired up. In loom it serves two roles: **wiring verification** (catch implemented-but-unintegrated code) and **code quality** (cleanup). Most valuable in **integration-verify** stages as a final gate over all implementation stages. > ⚠️ **`truths` is GONE** as a standalone field. Put dead-code checks in the first-class **`dead_code_check`** field (a goal-backward layer, run by `loom check`) or in **`acceptance`** (a build/lint command that exits non-zero on findings). A top-level `truths:` block is rejected as an unknown field. If dead code survives implementation it usually means: feature not wired (command unregistered, route unmounted), test code never run, refactor leftovers, or an incomplete implementation. ## The `dead_code_check` field (preferred, first-class) `dead_code_check` is a goal-backward check evaluated by `loom check <stage-id>`. Schema: ```yaml dead_code_check: command: "cargo build --message-format=short 2>&1" fail_patterns: ["warning: unused", "is never read", "never constructed"] ignore_patterns: ["generated.rs", "#[allow(dead_code)]"] ``` **Exactly how loom evaluates it** (`verify/goal_backward/dead_code.rs`): 1. Runs `command` in `working_dir`, **120 s timeout**, capturing stdout **and** stderr. 2. Scans the combined output **line by line**. 3. A line is ...