[iterate-4A] intro-video: re-baseline boot golden 50M -> 200M after clock fix

The clock fix (INSTRUCTIONS_PER_MS 10_000 -> 1_000_000, commit 645feb8) moves
the worker-hub +66 ms render gate from ~660k to ~66M instructions, so the old
-n 50M anchor is now pre-render (swaps=0) and no longer guards boot rendering.

Re-anchor sylpheed_n50m -> sylpheed_n200m: at -n 200M the fixed build renders
steadily (draws=3165, swaps=895) and the stable digest is deterministic across
repeated inline lockstep runs. Renames the golden, updates the test's -n and
doc comment, and refreshes tests/golden/README.md. Per the README's re-baseline
policy (intentional digest move -> separate commit).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/xenia-app/tests/sylpheed_oracles.rs

@@ -99,12 +99,15 @@ fn run_oracle(label: &str, max_instr: u64, golden_rel: &str) {
     }
 }
 
-/// Sylpheed boot to first VdSwap pair, captured at -n 50M lockstep.
-/// Catches regressions in: addi/addic semantics, kernel HLE for VdSwap path,
-/// thread spawning, file I/O for sound/config. With Phase A's swap fix landed,
-/// `swaps` should be 2 and `draws` 0 (Phase E gates draws>0).
+/// Sylpheed boot to steady rendering, captured at -n 200M lockstep.
+/// Catches regressions in: addi/addic semantics, kernel HLE for the VdSwap
+/// path, thread spawning, file I/O for sound/config, and boot render
+/// throughput. Re-anchored from 50M to 200M after the intro-video clock fix
+/// (INSTRUCTIONS_PER_MS 10_000 -> 1_000_000): the worker-hub +66 ms render
+/// gate now elapses at ~66M instr, so 50M is pre-render; by 200M boot is
+/// rendering steadily (`draws` 3165, `swaps` 895).
 #[test]
-#[ignore = "long-running; run via `cargo test ... -- --ignored sylpheed_n50m`"]
-fn sylpheed_n50m() {
-    run_oracle("sylpheed_n50m", 50_000_000, "tests/golden/sylpheed_n50m.json");
+#[ignore = "long-running; run via `cargo test ... -- --ignored sylpheed_n200m`"]
+fn sylpheed_n200m() {
+    run_oracle("sylpheed_n200m", 200_000_000, "tests/golden/sylpheed_n200m.json");
 }