feat(core): decouple structured output from Groupped trait

Introduce `StructuralData` sealed trait and `pack_structural!` /
`group_structural!` / `derive(StructuralData)` macros to control
structured rendering separately from grouping. `Groupped` no longer
requires `Serialize`.

1 files changed, 16 insertions, 6 deletions

diff --git a/examples/test-examples.toml b/examples/test-examples.toml
index 9c25781..149f2c6 100644
--- a/examples/test-examples.toml
+++ b/examples/test-examples.toml
@@ -234,16 +234,26 @@ expect.exit-code = 0
 expect.result = "Search path not provided"
 
 [[test.example-pack-err]]
-command = "find --json"
+command = "find Cargo.toml"
 expect.exit-code = 0
-expect.result = '{"name":"error_not_found"}'
+expect.result = "Not a directory: Cargo.toml"
 
 [[test.example-pack-err]]
-command = "find Cargo.toml"
+command = "find examples"
 expect.exit-code = 0
-expect.result = "Not a directory: Cargo.toml"
+expect.result = "Found directory: examples"
+
+[[test.example-pack-err]]
+command = "find-structural --json"
+expect.exit-code = 0
+expect.result = '{"name":"error_not_found_structural"}'
+
+[[test.example-pack-err]]
+command = "find-structural Cargo.toml --json"
+expect.exit-code = 0
+expect.result = '{"name":"error_not_dir_structural","info":"Cargo.toml"}'
 
 [[test.example-pack-err]]
-command = "find Cargo.toml --json"
+command = "find-structural examples --json"
 expect.exit-code = 0
-expect.result = '{"name":"error_not_dir","info":"Cargo.toml"}'
+expect.result = '{"inner":"examples"}'