Document ls --json breaking change and fix help example

- CHANGES: Add breaking change notice for --json output format
  (changed from array to {"workspaces": [...], "global_workspace_dirs": [...]})
- CHANGES: Add migration examples for jq users
- ls.py: Fix help text jq example from '.[] | .name' to '.workspaces[].name'

Author: tony

CHANGES

@@ -57,6 +57,17 @@ New `tmuxp search` command for finding workspace files:
 
 #### Enhanced ls Command (#1006)
 
+**Breaking change**: `--json` output format changed from array to object.
+
+- Old: `tmuxp ls --json` → `[{...}, {...}]`
+- New: `tmuxp ls --json` → `{"workspaces": [...], "global_workspace_dirs": [...]}`
+
+Migration:
+
+- Old: `tmuxp ls --json | jq '.[].name'`
+- New: `tmuxp ls --json | jq '.workspaces[].name'`
+- Alt: Use `--ndjson` for streaming individual workspace objects
+
 New output options for `tmuxp ls`:
 
 - `--tree`: Display workspaces grouped by directory

src/tmuxp/cli/ls.py

@@ -62,7 +62,7 @@
                 "tmuxp ls --json",
                 "tmuxp ls --json --full",
                 "tmuxp ls --ndjson",
-                "tmuxp ls --json | jq '.[] | .name'",
+                "tmuxp ls --json | jq '.workspaces[].name'",
             ],
         ),
     ),