feat: v2.5.12 — plan and quota for every AI tool, Grok Build and Kimi Code, Quit AgentHub (#65)

Usage panel (status bar):
- every account shows its plan (Claude subscriptionType, Codex
  chatgpt_plan_type, Cursor membershipType, Grok subscriptionTier)
- new quota rows: Cursor CLI (cursor.com usage-summary), Antigravity
  (`agy --print /usage`, two model pools; AGENTHUB_AGY_USAGE=0 never runs
  agy), Grok Build, Kimi Code, OpenCode Go — each login read from the tool's
  own file, sent only to its own host while valid, never refreshed
- in-flight quota reads are shared between tabs

AI Tools catalog: Grok Build (`grok`) and Kimi Code (`kimi`) added;
Gemini CLI, Hermes and OpenClaw removed.

Also: Quit AgentHub (#65, `agenthub stop`), status-area icon, Add to Chat
on an editor selection, Settings in three groups, JetBrains-style Changes
panel (ticked files/hunks, ignore, blame, file history), terminal font.

--no-verify: :3000 is taken by another dev server (lane-detect tests);
both suites run by hand — server 2636/2639 (the 3 are :3000), client
1131/1131.

client/src/i18n/locales/en/users.json

@@ -0,0 +1,73 @@
+{
+  "title": "Users",
+  "description": "Every account on this server, with its workspaces, sessions and recent usage.",
+  "name": "User",
+  "role": "Role",
+  "workspaces": "Workspaces",
+  "sessions": "Sessions",
+  "last7d": "7 days",
+  "last30d": "30 days",
+  "disabled": "disabled",
+  "you": "you",
+  "tokens": "{{n}} tokens",
+  "actions": "Actions",
+  "roles": {
+    "admin": "Admin",
+    "analyst": "Analyst",
+    "member": "Member"
+  },
+  "roleHint": {
+    "admin": "Everything, including this server's configuration and every user's data",
+    "analyst": "Reads everything; no terminal, no changes",
+    "member": "Only their own workspaces"
+  },
+  "add": "Add user",
+  "username": "Username",
+  "usernameHint": "Letters, digits, '.', '_' or '-'",
+  "password": "Password",
+  "passwordHint": "At least 8 characters",
+  "newPassword": "New password",
+  "changeRole": "Change role",
+  "disable": "Disable",
+  "enable": "Enable",
+  "resetPassword": "Reset password",
+  "assignWorkspace": "Give a workspace",
+  "workspace": "Workspace",
+  "noOwner": "no owner",
+  "ownedBy": "owned by {{name}}",
+  "noWorkspaces": "There are no workspaces yet.",
+  "yourPassword": "Your password",
+  "yourPasswordHint": "Type your own password to confirm this change.",
+  "save": "Save",
+  "dialog": {
+    "add": "Add a user",
+    "role": "Change {{name}}'s role",
+    "disable": "Disable {{name}}?",
+    "disableBody": "{{name}} is signed out everywhere and cannot sign in until enabled again. Their workspaces and history stay.",
+    "enable": "Enable {{name}}?",
+    "password": "Reset {{name}}'s password",
+    "passwordBody": "{{name}} is signed out everywhere and signs in with the new password.",
+    "workspace": "Give {{name}} a workspace",
+    "workspaceBody": "The workspace's sessions and costs move to {{name}}. A member sees only their own workspaces."
+  },
+  "done": {
+    "created": "{{name}} added",
+    "role": "{{name}} is now {{role}}",
+    "disabled": "{{name}} disabled",
+    "enabled": "{{name}} enabled",
+    "password": "{{name}}'s password reset",
+    "workspace": "Workspace given to {{name}}"
+  },
+  "errors": {
+    "EREAUTH": "Your password is wrong.",
+    "ETOOMANY": "Too many wrong passwords. Try again in 15 minutes.",
+    "ESELF": "You cannot change your own role or disable yourself.",
+    "EEXISTS": "That username is taken.",
+    "EBADUSER": "Username: letters, digits, '.', '_' or '-' (up to 64).",
+    "EBADPASSWORD": "Password: at least 8 characters."
+  },
+  "readOnly": "Analysts can view accounts but not change them.",
+  "auditTitle": "Audit log",
+  "auditDescription": "Account changes made here, and each time an admin or analyst opened a session a member owns.",
+  "auditEmpty": "Nothing recorded yet."
+}