amy's default stdout is now a YAML-ish render of the underlying result
map; the previous single-line JSON contract moves behind a global
`--json` flag. Errors mirror the same rule (`error: <code>: <detail>`
on stderr by default, JSON `{"error":...,"detail":...}` under --json).
Exit codes (0/1/2/124) and the --json shape itself are unchanged —
only the default presentation flips.
- Replaces Json.writeLine / Json.error with mode-aware
Output.emit / Output.error. The same Jackson mapper is reused for
on-disk JSON via Output.mapper.
- Adds `--json` to the global flag set in Main.kt; honoured even when
argument parsing fails so error JSON keeps shape under --json.
- Updates the test harness wrappers (amy_a / amy_b / amy_d in
cli/tests/{headless,dm,cache}/) and the few direct $AMY_BIN call
sites whose stdout is consumed via $() / 2>&1 — they now pass
--json so the existing jq pipelines keep working.
- Rewrites the README "Output contract" and DEVELOPMENT design
principles to describe the new default, and clarifies that only
--json is the public API; the text shape is allowed to drift.
Claude
03eb7be509