feat(cli): ship r-sma demo as a proven blueprint-data example (#159 cut 1)

Cut 1 of the hard-wired demo retirement — the copy+prove phase. The r-sma demo
strategy now ships as runnable blueprint data under crates/aura-cli/examples/
(r_sma.json closed 2/4, r_sma_open.json open), emitted from the current builder
so it is byte-for-byte the builder's serialization.

Two load-bearing proofs, captured while the builder is still alive:
- byte-fidelity: the shipped examples equal blueprint_to_json(&sma_signal(..)) —
  the "the copy is identical to the original" evidence the retirement method
  requires before any original is removed;
- grade anchor: `aura run examples/r_sma.json` reproduces the built-in
  `--harness r-sma` metrics byte-for-byte (expectancy_r/sqn/total_pips/n_trades).

Plus two property tests on the shipped copies (beyond the plan, kept as on-topic
proof strengthening): the closed example introspects to zero unbound params
(genuinely closed), and the open example lists exactly its two SMA-length axes
from the public gallery location.

Purely additive: the builder (sma_signal) and every inline r-sma surface are
retained. The recon showed deleting the builder has a large transitive closure
(the synthetic inline surface, the Strategy::RSma enum, ~40 integration tests);
that removal is cut 1b, a separate cycle, made safe by the byte-fidelity proof
frozen here.

Full workspace suite green; clippy -D warnings clean.

refs #159

crates/aura-cli/tests/graph_construct.rs

@@ -407,6 +407,13 @@ fn fixture(name: &str) -> String {
     format!("{}/tests/fixtures/{name}", env!("CARGO_MANIFEST_DIR"))
 }
 
+/// The absolute path of a demo blueprint shipped in the public examples/
+/// gallery (#159 copy+prove) — distinct from `fixture()`, which reads the
+/// internal tests/fixtures/ copies the emitter builds from.
+fn example(name: &str) -> String {
+    format!("{}/examples/{name}", env!("CARGO_MANIFEST_DIR"))
+}
+
 /// The id extracted from a `registered blueprint {id} ({path})` line.
 /// Prefix-tolerant across the #194 convention change (the display form dropped
 /// the glued `content:` prefix): the id is bare either way.
@@ -688,3 +695,39 @@ fn graph_params_accepts_an_op_script_matching_its_envelope() {
     assert_eq!(op_code, Some(0), "params on op-script exits 0: {op_out} {op_err}");
     assert_eq!(op_out, env_out, "op-script and envelope agree on the raw axis namespace");
 }
+
+/// Property (#159): the shipped closed example (`examples/r_sma.json`) is
+/// genuinely closed, not merely byte-identical to the builder — `graph
+/// introspect --params` on it reports zero unbound params. The Cut-1
+/// byte-fidelity proof (`shipped_r_sma_examples_are_byte_identical_to_the_builder`,
+/// main.rs) only pins the example's bytes to the builder's serialization; it says
+/// nothing about whether that serialization is actually closed. This pins the
+/// "closed" claim the demo makes to its audience.
+#[test]
+fn shipped_r_sma_example_is_genuinely_closed() {
+    let dir = temp_cwd("example-closed-params");
+    let (stdout, stderr, code) =
+        run_in(&dir, &["graph", "introspect", "--params", &example("r_sma.json")]);
+    assert_eq!(code, Some(0), "stdout: {stdout} stderr: {stderr}");
+    assert_eq!(stdout, "", "the closed example must leave zero params unbound");
+}
+
+/// Property (#159): the shipped open example (`examples/r_sma_open.json`) is a
+/// usable sweep-axis template from its public gallery location, not just a
+/// byte-identical artifact — `graph introspect --params` lists exactly the two
+/// unbound SMA lengths, in lowering order, matching the raw axis namespace the
+/// internal `sma_signal_open.json` fixture prints (#196). The byte-fidelity
+/// proof only checks the example's bytes match the builder; this checks the
+/// shipped copy is actually introspectable/bindable from where a consumer runs
+/// it.
+#[test]
+fn shipped_r_sma_open_example_lists_its_axis_namespace() {
+    let dir = temp_cwd("example-open-params");
+    let (stdout, stderr, code) =
+        run_in(&dir, &["graph", "introspect", "--params", &example("r_sma_open.json")]);
+    assert_eq!(code, Some(0), "stdout: {stdout} stderr: {stderr}");
+    assert_eq!(
+        stdout, "fast.length:I64\nslow.length:I64\n",
+        "the raw open params, in order, from the public gallery copy"
+    );
+}