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/1417-ffi-jni-class-07-all-runtimes.sx

@@ -0,0 +1,47 @@
+// Phase 2 step 2.7 (PLAN-FFI.md): xfail then green for the remaining
+// six type-introducer directive forms parsing with the same body
+// grammar as `#jni_class`. No codegen yet — Phase 3 picks up Obj-C
+// codegen, Phase 4 picks up Swift.
+//
+// The directives this step turns on:
+//   #jni_interface  — Java interface binding
+//   #objc_class     — Obj-C class binding
+//   #objc_protocol  — Obj-C protocol binding
+//   #swift_class    — Swift class binding (via @_cdecl bridge)
+//   #swift_struct   — Swift @frozen value-type binding
+//   #swift_protocol — Swift @objc-bridgeable protocol binding
+//
+// Internally the AST collapses into one `foreign_class_decl` node
+// carrying a `runtime` discriminator. Today the parser rejects each
+// of these because the lexer doesn't recognise the directive name.
+
+#import "modules/std.sx";
+
+IFoo :: #foreign #jni_interface("com/example/IFoo") {
+    bar :: (self: *Self) -> s32;
+}
+
+NSString :: #foreign #objc_class("NSString") {
+    length :: (self: *Self) -> s32;
+}
+
+NSCopying :: #foreign #objc_protocol("NSCopying") {
+    copy :: (self: *Self) -> *Self;
+}
+
+URL :: #foreign #swift_class("Foundation.URL") {
+    absoluteString :: (self: *Self) -> *void;
+}
+
+Date :: #foreign #swift_struct("Foundation.Date") {
+    timeIntervalSince1970 :: (self: *Self) -> f64;
+}
+
+Hashable :: #foreign #swift_protocol("Swift.Hashable") {
+    hash :: (self: *Self) -> s32;
+}
+
+main :: () -> s32 {
+    print("parse-only ok\n");
+    0;
+}