feat: workflow sql indent

BACKEND_DOCUMENTATION.MD

@@ -686,7 +686,12 @@ Node-graph automations (React Flow) run against the connection. A workflow's
   `{{input.path}}` (dotted paths supported, e.g. `{{input.row.id}}`); values are
   rendered as SQL literals (strings quoted with `''` doubling, numbers bare,
   booleans `TRUE`/`FALSE`, missing → `NULL`; a non-scalar value fails the node).
-  · `http`: `{ method, url, headers, body }` · `js`: `{ code }`
+  Add an `:ident` modifier — `{{input.field:ident}}` — to render the value as a
+  quoted SQL **identifier** instead (double-quoted with `""` doubling), for the
+  few statements that take a bare name and can't be parameterized, e.g.
+  `VACUUM (ANALYZE) {{input.relname:ident}}`. The value must be a non-empty
+  string; NULL/number/boolean fail the node so an identifier slot never silently
+  vanishes or injects. · `http`: `{ method, url, headers, body }` · `js`: `{ code }`
 - `js`: `{ code }` — the body receives `input`, returns the node output. Besides
   `input`/`console`, a curated **`crypto`** helper is in scope (no `require`):
   `crypto.hmac(algo, key, data, enc="hex")`, `crypto.hash(algo, data, enc="hex")`,

server.js

@@ -1361,10 +1361,23 @@ function runUserJs(code, input) {
 // Dialect-agnostic on purpose: single-quoted strings with '' doubling, bare
 // numeric literals, and NULL are valid in every roadmap dialect. Non-scalar
 // values are an error, not silently stringified.
+//
+// An optional `:ident` modifier — `{{input.field:ident}}` — renders the value
+// as a quoted SQL *identifier* (double-quoted with "" doubling) instead of a
+// literal, for the few statements that take a bare name and can't be
+// parameterized (e.g. VACUUM/ANALYZE/REINDEX <table>). Double-quoted identifiers
+// are standard SQL, so this stays dialect-agnostic. The value must be a
+// non-empty string; NULL/number/boolean are rejected so an identifier slot can
+// never silently vanish or inject.
 function substituteWorkflowInput(sql, input) {
-  return sql.replace(/\{\{\s*input((?:\.[A-Za-z_][A-Za-z0-9_]*)+)\s*\}\}/g, (_, path) => {
+  return sql.replace(/\{\{\s*input((?:\.[A-Za-z_][A-Za-z0-9_]*)+)\s*(?::\s*(ident))?\s*\}\}/g, (_, path, mod) => {
     let v = input
     for (const key of path.slice(1).split('.')) v = v?.[key]
+    if (mod === 'ident') {
+      if (typeof v !== 'string' || v === '')
+        throw new Error(`{{input${path}:ident}} must be a non-empty string identifier (got ${v === null || v === undefined ? 'null' : typeof v})`)
+      return `"${v.replace(/"/g, '""')}"`
+    }
     if (v === null || v === undefined) return 'NULL'
     if (typeof v === 'number' && Number.isFinite(v)) return String(v)
     if (typeof v === 'boolean') return v ? 'TRUE' : 'FALSE'