write down what today left unfinished

three, so none of it is re-derived:

agents-md-remaining — the five doc pairs landed; the runtime writers did not,
and that half is BROKEN rather than untidy. commanders, bots and plugin chats
write CLAUDE.md, opencode reads only AGENTS.md, so a commander run under
opencode is briefed with nothing and nothing reports it. names the three writers
by file. the 21 plugin repos are marked as the owner's to lead — not to sweep
unprompted.

marketplace-browse-by-tag — data layer done, UI not started. carries the two
questions that decide the shape: "All" as default, and whether the detail
replaces the grid or sits beside it, which is master-detail vs list-then-page and
contradicts how the screen is deliberately built today.

calendar-skill-never-used-by-an-agent — every recipe was run BY HAND and works;
no agent has ever read the skill and acted on a sentence. those are different
claims and only one of them is tested.

todo/plugin-ecosystem/marketplace-browse-by-tag.md

@@ -0,0 +1,32 @@
+---
+id: plugin-ecosystem/marketplace-browse-by-tag
+title: 'Marketplace: browse by tag — filter list, card grid, detail with a back button'
+theme: plugin-ecosystem
+status: open
+created: 2026-08-27
+date_source: stated
+order: 5
+---
+
+**The data layer is done** (`d381140d`): `PLUGIN_TAGS` is a closed vocabulary, every plugin declares its
+own tags in its manifest, the sync caches them, and `CatalogueEntry.tags` serves them normalised. All 21
+are tagged and every tag has at least three plugins behind it.
+
+**The UI is not started.** What the owner asked for, 2026-08-27:
+
+- tags listed down the LEFT, as the filter
+- plugins on the right as **cards in a grid**, app-store style — not the current master/detail list
+- clicking a card opens the detail, with a **back button returning where you were**
+
+Two things to settle before building:
+
+- **"All" has to be the default selection**, or a store that filters opens on nothing.
+- **Does the detail replace the grid or sit beside it?** A back button implies replace, which changes the
+  screen from master-detail to list-then-page. The current screen is explicitly built the other way
+  (`?selected=` rather than a route, deliberately — see `docs/navigation-audit.md`), so this is a real
+  change rather than a tweak.
+
+Whatever it becomes, the filter AND the selection both belong in the URL, or Back breaks.
+
+**More is wanted here beyond this** — the owner has said so, including "one very challenging but fun"
+thing not yet described.