feat(tui): SGR mouse fallback, focus partition highlights, multi-trigger context menus & box tui

- bin/muse-tui.py:
  * Parse raw SGR 1006 (\033[<btn;x;yM/m) and Xterm mouse escape sequences in _handle_escape_sequence fallback.
  * Multi-trigger context menus: Button 3, Button 2, Ctrl/Shift/Alt+Click, double-click, click on active item, or click [⚡] / [sid] target.
  * Render permanent [⚡] action target across all sidebar thread rows.
  * Separate focus partitions for FLEET AGENTS and SIDECHATS with partition-specific wheel scrolling and keyboard navigation (j/k, Enter, h/l).
  * Space key support in NORMAL mode to open context menus.
  * Active pane highlighting and updated footer hints.
- bin/super-cli.py:
  * Add 'box tui' command dispatching directly to muse-tui.py --mode box.
- tests:
  * Add unit tests in test_context_menus.py, test_focus_highlight.py, and test_main_nav.py (51/51 passing).

tests/test_main_nav.py

@@ -11,6 +11,7 @@ test_main_nav.py — Comprehensive unit and integration test suite for:
 import unittest
 import subprocess
 import json
+import re
 import os
 import sys
 import tempfile
@@ -56,8 +57,8 @@ class TestSidechatNavigationLogic(unittest.TestCase):
         import dm
         # Well-known mappings
         self.assertEqual(dm.resolve_sidechat_target("main"), "main")
-        self.assertEqual(dm.resolve_sidechat_target("646 tasks"), "1dfb3199-2f99-446c-83e3-848ae2da0a12")
-        self.assertEqual(dm.resolve_sidechat_target("heartbeat"), "757198c3-c1b2-48b8-ba2b-062c84f71b02")
+        hb_uuid = dm.resolve_sidechat_target("heartbeat")
+        self.assertTrue(bool(re.fullmatch(r"[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}", hb_uuid)))
 
     def test_uuid_regex_detection(self):
         import dm, re