feat(card): a folder shows every bundle under it, as the server does

`okf card <folder>` prints `okf_list` and `okf_describe` with no bundle
named, joined by `mcp_server.overview`, and computes nothing of its own:
one source, two doors. Chosen over a separate `--root` flag because the
skill's first step must be the same command whether it was pointed at a
bundle or at a folder of them; the rule that decides is discovery's own
(a directory carrying an `index.md` is a bundle). A bundle path prints its
card as before.

v1.1 order F, part F1.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

@@ -1397,6 +1397,21 @@ sub-questions in. The lines are capped at 48 000 bytes together
 (`lines_truncated` counts what a larger bundle leaves out), and a line lists at
 most 24 titles. The map replaced the card's flat `source_files` list.
 
+**Point it at a folder and it sees every bundle under it** (since v1.1 F):
+
+```sh
+okf card ~/okf                   # every bundle under the folder, each with its card
+```
+
+It prints what the server's `okf_list` and `okf_describe` give with no bundle
+named -- the listing (id, ref, concept count, directory), the directories that
+look like a bundle and cannot be read as one, and every bundle's card -- and it
+computes nothing of its own: the command calls the server's two functions. A
+bundle added or rebuilt under the folder is in the next run's answer with
+nothing regenerated. Pointed at one bundle, it prints that bundle's card as
+before; the command decides which it was given by the same rule discovery uses
+(a directory carrying an `index.md` is a bundle).
+
 `okf skill <bundle> --for-bundle` still writes the per-bundle form, with the
 identity and the numbers measured into the text — which is exactly what makes
 that file stale the moment the bundle is rebuilt. It refuses out loud when it