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/1033-errors-caller-location.sx

@@ -0,0 +1,22 @@
+// `#caller_location` (ERR step E4.1b). As a parameter's default value it
+// resolves to a `Source_Location` of the CALL site — file, line:col, and the
+// enclosing function — rather than the callee's signature. Explicitly
+// forwarding a `Source_Location` through an inner call preserves the outermost
+// site (so a logging wrapper reports where IT was called). Expected exit: 0.
+
+#import "modules/std.sx";
+
+note :: (loc: Source_Location = #caller_location) {
+    print("note from {} (line {})\n", loc.func, loc.line);
+}
+
+// Forwards its own caller location through to `note`.
+wrap :: (loc: Source_Location = #caller_location) {
+    note(loc);
+}
+
+main :: () -> s32 {
+    note();              // call site → func main
+    wrap();              // forwarded → still reports this line in main
+    return 0;
+}