fix(aura-cli, docs): fieldtest bugs — the non-literal override prose + the guide's family-id shape

- parse_override_tokens distinguishes the grammar fault (no '=' / no
  dotted path — prose unchanged) from a shape-valid token whose VALUE
  fails the scalar-literal parse: the refusal now names the value and
  the literal requirement (styled after the kind-mismatch sibling)
  instead of falsely claiming a NODE.PARAM=VALUE violation. RED-first;
  exit stays 2 on both branches.
- the authoring guide's multi-regime family ids corrected to the
  executor's real shape (infix -r{k} after the window segment, -r0
  explicit on the default regime), and §1's name-op paragraph no
  longer claims naming dissolves same-name trace overwriting (that
  trace-dir question is tracked on #311, not resolved here).

crates/aura-cli/tests/exec.rs

@@ -667,6 +667,25 @@ fn exec_override_malformed_token_refuses_with_usage() {
     assert!(out.contains("NODE.PARAM=VALUE"), "stdout/stderr: {out}");
 }
 
+/// B2 (2026-07-26 harvest fieldtest): `fast.length=abc` IS in the
+/// `NODE.PARAM=VALUE` grammar — a dotted path, an `=`, a value — so the
+/// grammar is not what is wrong here; `abc` simply is not a scalar literal.
+/// `parse_override_tokens` must not misreport this as a shape violation
+/// (the same "expects NODE.PARAM=VALUE" prose a token missing `=` gets);
+/// it must name the offending value and that a scalar literal is required,
+/// styled after the kind-mismatch sibling
+/// (`exec_override_kind_mismatch_refuses_with_prose_not_the_debug_struct`).
+#[test]
+fn exec_override_non_literal_value_names_the_value_not_a_grammar_fault() {
+    let (out, code) = run_code(&["exec", "examples/r_sma.json", "--override", "fast.length=abc"]);
+    assert_eq!(code, Some(2), "stdout/stderr: {out}");
+    assert!(out.contains("abc"), "the offending value must be named: {out}");
+    assert!(
+        !out.contains("NODE.PARAM=VALUE"),
+        "must not misreport a non-literal value as a NODE.PARAM=VALUE shape violation: {out}"
+    );
+}
+
 /// An override path naming no param of the blueprint (open or bound) refuses
 /// with `override_paths`' own prose (`member.rs:768-771`), pointing at the
 /// live axis-discovery verb (`aura graph introspect --params`) — the retired