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/lib/cc-discovery.js

@@ -215,10 +215,15 @@ function readSkillsAt(scope, claudeDir) {
   return skills.sort((a, b) => a.name.localeCompare(b.name));
 }
 
+/**
+ * @param {{scope?: string, cwd?: string, userClaudeDir?: string}} opts
+ *   `userClaudeDir` = whose user scope to read (a member's `~/.claude` under
+ *   S3); the host's Claude home when absent.
+ */
 function readSkills(opts = {}) {
   const out = [];
   if (opts.scope !== "project") {
-    out.push(...readSkillsAt("user", getClaudeHome()));
+    out.push(...readSkillsAt("user", opts.userClaudeDir || getClaudeHome()));
   }
   if (opts.scope !== "user") {
     out.push(...readSkillsAt("project", getProjectClaudeDir(opts.cwd)));
@@ -257,7 +262,7 @@ function readSimpleMdSurface(subdir) {
   return (opts = {}) => {
     const out = [];
     if (opts.scope !== "project") {
-      out.push(...readMdFilesAt("user", getClaudeHome(), subdir));
+      out.push(...readMdFilesAt("user", opts.userClaudeDir || getClaudeHome(), subdir));
     }
     if (opts.scope !== "user") {
       out.push(...readMdFilesAt("project", getProjectClaudeDir(opts.cwd), subdir));
@@ -423,18 +428,18 @@ function readPluginContributions(installPath) {
   };
 }
 
-function readEnabledPluginsMap() {
-  const userSettings = readJson(path.join(getClaudeHome(), "settings.json"));
+function readEnabledPluginsMap(home = getClaudeHome()) {
+  const userSettings = readJson(path.join(home, "settings.json"));
   if (!userSettings.ok || !userSettings.data) return {};
   const ep = userSettings.data.enabledPlugins;
   return ep && typeof ep === "object" ? ep : {};
 }
 
-function readPlugins() {
-  const home = getClaudeHome();
+/** @param {string} [home] whose Claude home (a member's under S3); the host's by default. */
+function readPlugins(home = getClaudeHome()) {
   const manifestPath = path.join(home, "plugins", "installed_plugins.json");
   const manifest = readJson(manifestPath);
-  const enabledMap = readEnabledPluginsMap();
+  const enabledMap = readEnabledPluginsMap(home);
   const plugins = [];
   if (manifest.ok && manifest.data && manifest.data.plugins) {
     for (const [pluginKey, instances] of Object.entries(manifest.data.plugins)) {
@@ -847,7 +852,11 @@ function isSecretConfigPath(resolved) {
   const base = path.basename(resolved);
   if (!base.endsWith(".md") && require("./ai-tools").CONFIG_SECRET_RE.test(base)) return true;
   const rel = path.relative(getClaudeHome(), resolved);
-  if (!rel.startsWith("..") && !path.isAbsolute(rel) && rel.split(path.sep)[0].startsWith("agenthub-"))
+  if (
+    !rel.startsWith("..") &&
+    !path.isAbsolute(rel) &&
+    rel.split(path.sep)[0].startsWith("agenthub-")
+  )
     return true;
   // AgentHub's data dir is no Claude config: it holds the database, the push
   // keys and every gateway pane's settings file WITH its live pane token.