authoring-smell-rules

/mache:authoring-smell-rules — Add a find_smells rule

A smell rule is a SQL query over mache's projected graph tables plus metadata. Rules live in smellRegistry in cmd/smell_rules.go (built-ins) or in $MACHE_SMELL_RULES_DIR (external, appended at init). Each rule is one SmellRule:

SmellRule{
    ID:          "magic_int_in_comparison", // stable; the MCP/CLI argument
    Languages:   []string{"go"},            // match _source.language; empty = any
    Description:  "...",                     // shown in the rules listing
    Requires:    []string{"_ast", "nodes"}, // tables the query reads (capability gate)
    ScopeColumn: "lit.source_id",            // SQL expr compared to source_id; "" disables scoping
    Query: `SELECT source_id, node_id, start_byte, end_byte, start_row, start_col, <metric> AS metric
            FROM ... WHERE ... %s`,          // %s = optional injected scope clause
    DefaultMinMetric: 10,                    // threshold when caller omits min_metric (0 = return all)
    Severity:    SeverityWarn,               // off | warn | error
    Tags:        []string{"complexity"},     // free-form; CLI --tags selection (cap 3-5)
}

The query contract

Return columns in this order: source_id, node_id, start_byte, end_byte, start_row, start_col, metric. The %s placeholder receives the scope clause (so a rule can be run against one file). The handler applies min_metric filtering on the metric column, but does not sort — rows come back in the query's order, so if you want top-N-by-metric you must add ORDER BY metric DESC to your SQL yourself (the metric-bearing built-ins do). Use 0 AS metric for non-metric rules.

⚠ The capability split (Requires) — get this right

What tables exist depends on who built the .db: