feat(box): passkey fetch, agent key-approval flow, unified lookups, tmux agent UX

- box passkey [show|fetch] (+ muse passkey): documents VM-only passkey
  (/srv/box/passkey.txt, fallback /etc/netvm/passkey.txt on 34.139.37.135),
  probes VM over SSH with graceful fallback; --json supported. No secrets on bl.
- approvals: request_key_approval / check_node_key_request; KEY_APPROVAL status
  surfaced in `box approvals check`; allow/deny resolve + audit to box-ctl.jsonl;
  never auto-approved. New `box approvals request-key <node> --reason`.
- box lookup (summary|fleet|threads|unread|approvals|key|docs) and docs-lookup
  engine with lookup_internal/ database (docs_internal symlink).
- muse-tmux: non-TTY attach falls back to scrollback capture; prune NameError fix.
- box/muse passthrough for tmux/muse/docs; thread list/view alias + prefix resolve.
- Docs: AGENTS.md, AGENT-TOOLING.md, BOX-WEB-SURFACE-GUIDE.md, README.
- Tests: key-approval + passkey tests; sync stale sidechat UUIDs and manifest name.
- .gitignore runtime trackers (subagent-sessions, conversation-nudge-tracker).

bin/muse-tmux.py

@@ -6,6 +6,7 @@ Socket location: /tmp/tmux-muse.sock (shared across fleet agents & super).
 import sys
 import os
 import re
+import time
 import subprocess
 import argparse
 
@@ -181,6 +182,13 @@ def cmd_attach(args):
     session = args.session
     node = getattr(args, "node", None)
     container = getattr(args, "container", None)
+    
+    # Graceful non-interactive fallback for autonomous agents
+    if not sys.stdin.isatty():
+        sys.stderr.write(f"Notice: Non-interactive terminal (no tty). Capturing recent scrollback for '{session}':\n\n")
+        setattr(args, "lines", getattr(args, "lines", 30) or 30)
+        return cmd_capture(args)
+
     if node:
         cmd = ["/home/super/Projects/NetVM/bin/netvm-exec.sh", node, "--", TMUX_BIN, "-S", f"/tmp/tmux-{node}.sock", "attach", "-t", session]
         os.execv(cmd[0], cmd)