Improve UX and add JSON output

[dylandreimerink]

This PR merges the separate sub commands for collection and program listing into a singular list command for the sake of user experience.

This PR also adds JSON outputs to all commands to allow for usage in scripts or for data extraction.

[Copilot]

Pull request overview

This PR streamlines the CLI UX by consolidating the prior collection/program subcommands into a single list command, and introduces a global --json output mode to make command results script-friendly.

Changes:

• Replace collection and program subcommands with a unified list {collection} [program] command.
• Add a persistent --json / -j flag and JSON output support for list and version.
• Update tests/docs to reflect the new command surface.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
README.md	Updates usage examples/docs to the new list command.
cmd/stackwhere/main.go	Adds persistent --json flag and registers only list + version.
cmd/stackwhere/version.go	Adds JSON output mode for version and structures version info.
cmd/stackwhere/list.go	Implements merged list behavior (collection summary vs program detail) and JSON output.
cmd/stackwhere/list_test.go	Updates slot-usage test for exported fields; adds stack-usage test.
cmd/stackwhere/collection.go	Removes deprecated collection subcommand implementation.
cmd/stackwhere/collection_test.go	Removes deprecated collection test (moved/replaced elsewhere).

Comments suppressed due to low confidence (5)

cmd/stackwhere/list.go:62

• --call-stack currently has no effect on JSON output: getStackSlotUsage always populates Callstack, and the JSON encoder emits it whenever non-empty even if the flag is false. Consider omitting/clearing Callstack (or computing it conditionally) unless --call-stack is enabled to keep JSON and text outputs consistent.
  cmd/stackwhere/list.go:71
• Non-JSON output is written via fmt.Printf, which bypasses Cobra's configured output writer. Use cmd.OutOrStdout() (e.g., fmt.Fprintf(cmd.OutOrStdout(), ...) or cmd.Printf) so output can be redirected/captured consistently (including in tests).
  cmd/stackwhere/list.go:249
• Sorting comparator returns only the stack-usage difference, but the comment says it also sorts by name. When two programs have equal stack_usage, slices.SortFunc may produce nondeterministic ordering; add a secondary name comparison (and avoid int64 subtraction -> int cast) to ensure a total order.
  cmd/stackwhere/list.go:275
• Non-JSON output is printed with fmt.Printf, which ignores Cobra's output writer. Prefer writing to cmd.OutOrStdout() so users/tests can redirect output consistently.
  cmd/stackwhere/list.go:62
• New JSON-output paths aren’t covered by tests. Adding a small test that runs the command with --json and asserts the output is valid JSON (and respects flags like --call-stack) would help prevent regressions.

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