feat: Discard all, claude-style image pastes, large local drops, per-account / list

- Changes panel: **Discard all** beside Commit discards every non-conflicted
  file in one `discard`, after a dialog naming how many untracked files go.
- Terminal: a `claude` pane gets dropped/pasted images as bare paths (shown as
  `[Image #n]`) and other files as `@` mentions (`claudePastes`); a local
  browser's copied `file://` paths and text-drag file lists paste by path.
- `POST /api/run/drop-file`: a loopback browser outside server mode may drop
  up to 2 GB, streamed to disk; remote stays 20 MB.
- cc-config skills/commands/plugins read the USER scope of the account the
  pane runs as (S3 member home by `cwd`), never another user's or the host's
  for a non-admin without an account; the run form passes its cwd to plugins.

server/routes/cc-config.js

@@ -95,16 +95,45 @@ function cwdOf(req) {
 }
 
 /**
- * `{scope, cwd}` for the two lists a member may read (the run form's `/`
+ * The Claude home whose USER skills, commands and plugins a request's sessions
+ * load — so the run form's `/` list matches what its pane's Claude can call.
+ * Under S3 a pane runs as its FOLDER's account: `?cwd=` picks that account; a
+ * non-admin with no `?cwd=` reads their own. Undefined = the host's (local
+ * mode, or an admin in a host folder / the Config Explorer); null = none, for
+ * a non-admin with no account of their own — another user's or the host's
+ * skills are never listed as theirs.
+ */
+function userClaudeDir(req) {
+  if (!req.user) return undefined;
+  const runAs = require("../lib/run-as");
+  const cwd = typeof req.query.cwd === "string" && req.query.cwd;
+  let acct = null;
+  try {
+    if (cwd && path.isAbsolute(cwd)) acct = runAs.ownerForRead(path.resolve(cwd));
+    else if (req.user.role !== "admin") acct = runAs.accountForUser(req.user.username);
+  } catch {
+    acct = null;
+  }
+  if (acct) return path.join(acct.home, ".claude");
+  return req.user.role === "admin" ? undefined : null;
+}
+
+/**
+ * `{scope, cwd, userClaudeDir}` for the two lists a member may read (the run form's `/`
  * autocomplete). Server mode keeps a member's project items to their own
  * workspaces: another folder answers 403 EFOLDER, and with no `?cwd=` there is
  * no project at all (never the dashboard's own working directory). Returns null
  * once it has answered; `none` = nothing to list.
  */
 function listOpts(req, res) {
-  const opts = { scope: scopeOf(req), cwd: cwdOf(req) };
-  if (scope.memberId(req) == null) return opts;
+  const opts = { scope: scopeOf(req), cwd: cwdOf(req), userClaudeDir: userClaudeDir(req) };
   const asked = typeof req.query.cwd === "string" && req.query.cwd;
+  // No account of their own: only a named workspace's project items, if any.
+  if (opts.userClaudeDir === null) {
+    if (opts.scope === "user" || !asked) return { none: true };
+    opts.scope = "project";
+  }
+  if (scope.memberId(req) == null) return opts;
   if (!asked) return opts.scope === "project" ? { none: true } : { ...opts, scope: "user" };
   if (!path.isAbsolute(asked) || !scope.insideOwnWorkspace(req, path.resolve(asked))) {
     res.status(403).json({
@@ -137,8 +166,10 @@ router.get("/output-styles", (req, res) => {
   res.json({ items: cc.readOutputStyles({ scope: scopeOf(req), cwd: cwdOf(req) }) });
 });
 
-router.get("/plugins", (_req, res) => {
-  res.json(cc.readPlugins());
+router.get("/plugins", (req, res) => {
+  const home = userClaudeDir(req);
+  if (home === null) return res.json({ manifestPath: null, manifestExists: false, plugins: [] });
+  res.json(cc.readPlugins(home));
 });
 
 router.get("/mcp", (req, res) => {