feat: v2.6.0 — Chat UI composer (+ menu, project files, activity panel, permission mode, Stop), git on a workspace's extra folders (#70), long paste as a file (#68), S3 server mode (experimental)

Chat UI:
- Each Claude/Codex session keeps its own chat/terminal view; Settings only
  sets how new sessions open.
- Composer + menu: upload, project files and folders (#54, also dragged from
  the Files/Changes tree), context files, recent uploads, skills, plugins.
- Activity side panel (progress, outputs, files read, uploads, memory,
  skills, connectors) with a file preview; edited-file counts per turn.
- Permission-mode chip (Shift+Tab steps, read back from the pane:
  server/lib/pane-mode.js, GET|POST /api/run/:id/permission-mode).
- Stop (Esc) while the main agent works; the status is checked per agent
  (with session_id /api/agents ignores its status filter) and re-read every
  5 s while Stop shows.
- Dropped images shown in the conversation (GET /api/run/drop/:name, the
  requester's own drop dir), full-size viewer.
- A plain-text paste over 5,000 characters is attached as pasted-text.txt,
  so no prompt reaches tmux/argv limits (#68).

Changes panel: every /api/lanes/:id/git* route takes ?source=<lane_sources
id> (sourceFolder; ENOSOURCE otherwise) and a folder picker switches the
whole panel to a workspace's extra folder (#70).

Server mode S3 (one Linux user per account) — experimental, verified with
fake sudo plus a P6 managed-settings spike on a test account:
- member tmux listing runs in the background (cached, 15 s => unknown);
- transcript snapshot copy is async, chunked, temp file + rename;
- Express Layer patch only on Express 4;
- tmux capturePane/sendKey go to the member's own server.

Docs: the multi-user design moved in as docs/plans/server-mode/README.md
(the AgentHub-Server repo is gone); S3-PLAN P6 result; LANES/API/openapi.

client/index.html

@@ -30,7 +30,7 @@
     <title>AgentHub - SmartGift Solution</title>
     <meta
       name="description"
-      content="Real-time monitoring platform for Claude Code agent activity. Track sessions, monitor agents, visualize analytics, manage cost tracking, and receive browser notifications - all with live WebSocket updates."
+      content="Run, steer and track your AI coding agents in one browser tab: workspaces with live terminals for Claude Code, Codex and more, built-in Git, chat replay, usage and cost tracking, and alerts - local-first and real-time."
     />
     <meta
       name="keywords"
@@ -45,23 +45,23 @@
     <meta property="og:title" content="AgentHub - SmartGift Solution" />
     <meta
       property="og:description"
-      content="Real-time monitoring platform for Claude Code agent activity. Track sessions, monitor agents, visualize analytics, manage cost tracking, and receive browser notifications - all with live WebSocket updates."
+      content="Run, steer and track your AI coding agents in one browser tab: workspaces with live terminals for Claude Code, Codex and more, built-in Git, chat replay, usage and cost tracking, and alerts - local-first and real-time."
     />
-    <meta property="og:image" content="/og-image.svg" />
+    <meta property="og:image" content="/og-image.png" />
     <meta property="og:image:width" content="1200" />
     <meta property="og:image:height" content="630" />
-    <meta property="og:image:type" content="image/svg+xml" />
-    <meta property="og:image:alt" content="AgentHub - real-time Claude Code monitoring" />
+    <meta property="og:image:type" content="image/png" />
+    <meta property="og:image:alt" content="AgentHub - run, steer and track your AI coding agents" />
 
     <!-- Twitter / X Card -->
     <meta name="twitter:card" content="summary_large_image" />
     <meta name="twitter:title" content="AgentHub - SmartGift Solution" />
     <meta
       name="twitter:description"
-      content="Real-time monitoring platform for Claude Code agent activity. Sessions, Kanban board, analytics, cost tracking, browser notifications, and WebSocket push."
+      content="Run, steer and track your AI coding agents in one browser tab: workspaces with live terminals for Claude Code, Codex and more, built-in Git, chat replay, usage and cost tracking, and alerts - local-first and real-time."
     />
-    <meta name="twitter:image" content="/og-image.svg" />
-    <meta name="twitter:image:alt" content="AgentHub - real-time Claude Code monitoring" />
+    <meta name="twitter:image" content="/og-image.png" />
+    <meta name="twitter:image:alt" content="AgentHub - run, steer and track your AI coding agents" />
     <meta name="twitter:creator" content="@smartgift" />
 
     <!-- JSON-LD structured data -->
@@ -70,7 +70,7 @@
         "@context": "https://schema.org",
         "@type": "WebApplication",
         "name": "AgentHub",
-        "description": "Real-time monitoring platform for Claude Code agent activity. Tracks sessions, agents, tool events, token usage analytics, cost tracking, and browser notifications via native hooks with live WebSocket push.",
+        "description": "Run, steer and track your AI coding agents in one browser tab: workspaces with live terminals for Claude Code, Codex and more, built-in Git, chat replay, usage and cost tracking, and alerts - local-first and real-time.",
         "applicationCategory": "DeveloperApplication",
         "operatingSystem": "Windows, macOS, Linux",
         "softwareVersion": "1.0.0",