test: migrate examples to XXXX-category-name layout + split expected streams

Rename all example tests/companions to the XXXX-category-test-name scheme
(per-category 100-blocks: basic 0010, types 0100, ... errors 1000,
diagnostics 1100, ffi 1200, ffi-objc 1300, ffi-jni 1400, vectors 1500,
platform 1600). Companions and dir/C fixtures move in lockstep with their
parent test; #import/#source/#include paths rewritten to match.

Expected output now lives in examples/expected/ (a sibling dir of the
tests) split into three streams per the new convention:
  <name>.exit / <name>.stdout / <name>.stderr  (+ optional <name>.ir)

run_examples.sh rewritten: scans examples/ and issues/ for an
expected/<name>.exit marker, captures stdout and stderr separately (no
more 2>&1), compares each stream + exit + optional IR snapshot.

Behavior validated unchanged: every renamed test reproduces its prior
merged output + exit (diffs limited to file paths/basenames embedded in
diagnostics + traces, which correctly reflect the new names). Suite:
292 passed, 0 failed. 50-smoke.sx split + issue relocation + docs follow
in subsequent commits.

examples/1034-errors-interp-frames.sx

@@ -0,0 +1,23 @@
+// `trace.print_interpreter_frames()` (ERR step E4.1). At comptime (`#run`) it
+// dumps the interpreter's active sx call-frame chain (most recent call last) to
+// the build output; in compiled code it folds to nothing (no interpreter stack
+// — the only real caller is `process.exit`'s dead `is_comptime()` branch). The
+// dump frame itself is omitted; frame source locations await IR-offset
+// resolution, so only names print today. Expected exit: 0.
+
+#import "modules/std.sx";
+trace :: #import "modules/trace.sx";
+
+probe :: () {
+    trace.print_interpreter_frames();    // dumps the chain: __run_0 → inner → probe
+}
+
+inner :: () {
+    probe();
+}
+
+#run inner();                             // top-level #run drives the chain
+
+main :: () -> s32 {
+    return 0;
+}