fix(gui-x): stop empty/grey block on Ubuntu/GNOME; safer geometry

[roman-ryzenadvanced]

Problem

The X Edition Warp-style Linux GUI was opening as an empty grey block on Ubuntu/GNOME.

Root cause

1. root.overrideredirect(True) made the WM treat the window as a special undecorated type whose content is not painted until the user interacts with it.
2. root.state("zoomed") in __init__.py was applied to an already-maximizing window with conflicting geometry, leaving the content area blank.
3. No update_idletasks() / deiconify() after geometry changes, so the WM never flushed the new size to the X server.

Fix

• src/gui_x/__init__.py — drop state("zoomed"); add update_idletasks() + deiconify() so the window is visible immediately.
• src/gui_x/launcher.py — disable the overrideredirect branch on Linux; fall back to native window decorations (more reliable on every DE).
• src/gui_x/titlebar.py — keep the Python 3.14 winfo_children() try/except patch.

Test

Full widget tree visible at 1400x900 with Catppuccin Mocha background; sidebar (48px) + content (1352px) both render.

Tk(bg=#0C0E16, geom=1400x900+1604+1064, vis=1)
  Frame(bg=#0C0E16, geom=1400x900+0+0, vis=1)
    Frame(bg=#0C0E16, geom=1400x900+0+0, vis=1)
      Sidebar(bg=#161928, geom=48x900+0+0, vis=1)
      Frame(bg=#0C0E16, geom=1352x900+48+0, vis=1)

Notes

• Untracked files (auto_patch_trae_solo.py, discord_controller.py, trae-solo-local/, install_patched*.sh, install_trae_solo.sh, run_and_install_trae_solo.sh) are deliberately NOT included in this PR — they're from an unrelated work session.