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/0605-comptime-aggregate-global.sx

@@ -0,0 +1,31 @@
+#import "modules/std.sx";
+
+// MEM Phase 1.4 regression: an aggregate (struct) returned from a `#run`
+// initializer must serialize correctly into the static binary, not
+// silently collapse to a zero-init constant.
+//
+// Before Phase 1.4 the LLVM `valueToLLVMConst` only handled int/float/bool
+// and dropped everything else into `LLVMConstNull` — so a global like
+// `POINT :: #run make_point();` ended up emitting `{0, 0}` regardless of
+// what the interp computed. Reading POINT.x would give 0, hiding the bug.
+//
+// Also exercises type inference at the `NAME :: #run expr;` binding site:
+// without an explicit annotation, the global's type is taken from the
+// comptime expression's return shape (here, `Point`).
+
+Point :: struct {
+    x: s32;
+    y: s32;
+}
+
+make_point :: () -> Point {
+    return Point.{ x = 7, y = 13 };
+}
+
+POINT :: #run make_point();
+
+main :: () -> s32 {
+    print("POINT.x = {}\n", POINT.x);
+    print("POINT.y = {}\n", POINT.y);
+    return 0;
+}