fix(ipc): support querying against duplicate bar names

It is possible/valid to define multiple bars by the same name by setting `name` on the top-level bar object, but not specifying monitors. This updates IPC to support this scenario.

Allow IPC to act on multiple bars by the same name (#777)

docs/Controlling Ironbar.md

@@ -10,7 +10,8 @@ You can also view help per sub-command or command, for example using `ironbar va
 The CLI supports plaintext and JSON output. Plaintext will:
 
 - Print `ok` for empty success responses
-- Print the returned body for success responses
+- Print the returned body for each success response
+  - Some commands act on multiple objects, in which case the CLI will print one line for each body.
 - Print `error` to followed by the error on the next line for error responses. This is printed to `stderr`.
 
 Example:
@@ -150,6 +151,9 @@ Each key/value pair is on its own `\n` separated newline. The key and value are
 
 ### `bar`
 
+> [!NOTE]
+> If there are multiple bars by the same name, the `bar` subcommand will act on all of them and return a `multi` response for commands that get a value.
+
 #### `show`
 
 Forces a bar to be shown, regardless of the current visibility state.
@@ -324,6 +328,17 @@ The operation completed successfully, with response data.
 }
 ```
 
+### `multi`
+
+The operation completed successfully on multiple objects, with response data.
+
+```json
+{
+  "type": "multi",
+  "values": ["lorem ipsum", "dolor sit"]
+}
+```
+
 ### `error`
 
 The operation failed.
@@ -335,4 +350,4 @@ Message is optional.
   "type": "error",
   "message": "lorem ipsum"
 }
-```
+```