feat(cc-config): list a plugin's skills, agents and commands by name

A plugin card showed "7 skills, 5 agents" and nothing more — the counts
were the whole story, so finding out WHICH skills a plugin ships meant
opening its install directory by hand. The contribution chips are now
buttons: clicking one expands a list naming each artifact with its
description, one surface open at a time. Commands render with their
slash. Hooks stay a plain chip — a plugin's hooks are matcher/command
pairs declared inline in plugin.json, not named artifacts.

`contributes.items` carries the four surfaces server-side; the existing
counts keep their type and are now derived from those lists, so a chip
reading "3 commands" can never sit beside a list holding two.

That also fixes a real blind spot. Each surface was read only from the
conventional install subdirectory, but plugin.json may declare its own
paths — this repo's own `ccam` lists three files under
plugins/ccam/commands/ and keeps commands/ empty, so it reported zero
commands. Both sources are now read and de-duplicated. A declared path
resolving outside the plugin's install directory is dropped: a manifest
is third-party data and must not turn the dashboard into an arbitrary
file reader.

Also pins the Refresh button's width: both labels share one grid cell so
the button is always as wide as "Refreshing…" / "Đang làm mới…" and no
longer resizes the toolbar when the state flips. Measuring the longest
real string beats a min-width that would be wrong in the next language.

Verified: npm run test:server (1370 tests, +6 for the new discovery),
npm run test:client (457, +3 for the expand behaviour), tsc --noEmit,
prettier and check-headers clean. Docs synced: docs/API.md, openapi.yaml
(new CcConfigPluginItem schema), ARCHITECTURE.md, docs/PLUGINS.md.

docs/API.md

@@ -1592,6 +1592,8 @@ POST /api/cc-config/marketplaces/action   Body: { name, action: update|remove }
 
 `scope` is `"user"`, `"project"`, or `"auto-memory"`. `type` is one of `skills`, `agents`, `commands`, `output-styles`, `memory`, `auto-memory`. `name` is required for everything except `memory` (which is `CLAUDE.md` itself). On `PUT`, `name` is validated against `^[A-Za-z0-9][A-Za-z0-9._-]{0,63}$` (for `auto-memory` it must instead be a flat `*.md` filename). Settings are returned with secret-like keys (matching `/token|secret|password|api[_-]?key|auth/i`) replaced by `"<redacted>"`.
 
+`GET /api/cc-config/plugins` returns each installed plugin's `contributes` block: the `skills` / `agents` / `commands` / `outputStyles` / `hooks` counts, plus `contributes.items` listing the first four surfaces **by name** (`[{ name, description, file }]`) so the UI can show *which* artifacts a plugin ships, not only how many. `name` is the file's frontmatter `name` when it declares one — the string Claude Code actually addresses it by — otherwise the filename. Each surface covers both the conventional directory (`skills/`, `agents/`, `commands/`, `output-styles/`) **and** any path `plugin.json` declares under that key: a plugin that lists its commands explicitly and keeps nothing in `commands/` (this repo's own `ccam` does) previously reported zero. A declared path that resolves outside the plugin's install directory is ignored — a third-party manifest must not make the dashboard read arbitrary files. The counts are always the matching list's length. `hooks` has no `items` list: a plugin's hooks are matcher/command pairs declared inline in `plugin.json`, not named artifacts.
+
 `GET /api/cc-config/memory` also surfaces the per-project file-based memory store — every `*.md` under `~/.claude/projects/<slug>/memory/` (the common pattern of a `MEMORY.md` index plus one file per remembered fact). Those items have `scope: "auto-memory"` and carry `project` (the `projects/<slug>` dir name), `name` (filename), `isIndex` (true for `MEMORY.md` / `INDEX-*.md`, which sort first), and parsed `frontmatter`. They are **editable**: `PUT`/`DELETE /api/cc-config/file` accept `{ scope: "auto-memory", type: "auto-memory", project, name, content? }` and create a timestamped backup under `<memory-dir>/.cc-config-backups/auto-memory/` before mutating (an invalid `project` slug returns `EBADPROJECT`). `GET /api/cc-config/backups` lists these with `scope: "auto-memory"` and `project` set. Bodies are also readable via `GET /api/cc-config/file` (they live under `CLAUDE_HOME`).
 
 **`PATCH /api/cc-config/settings` (key merge).** `scope` is `"user"`, `"project"`, or `"project-local"` (`settings.local.json`). `set` maps dotted key paths to JSON values; `unset` is a list of dotted key paths to delete. The server re-reads the target file **unredacted**, applies only the named keys, backs it up under `<dir>/.cc-config-backups/settings/`, and writes atomically — so keys the UI never displayed (including secret-valued ones) survive byte-for-byte. Returns `{ path, backupPath, created, changed }`. Hooks are edited through this same route, as `set: { "hooks.PreToolUse": [{ matcher, hooks: [{ type, command, timeout? }] }] }` — i.e. `settings.json`'s own nested shape, not the flattened shape `GET /hooks` returns. Errors: `EBADSCOPE` (unknown scope), `EBADNAME` (a key segment outside `[A-Za-z0-9_$][A-Za-z0-9._$-]*`, or `__proto__`/`prototype`/`constructor`), `EREDACTED` (400 — the payload contains the `<redacted>` placeholder, which would destroy a real secret), `EBADJSON` (409 — the file on disk is not valid JSON; it is left untouched rather than clobbered), `ETOOLARGE`. The project layers always resolve against the **server's** cwd; `?cwd=` is honoured on reads only, never on this write.