Add T3 Code to the AI install menu (#7496)

t3code-bin is in the Omarchy repo now, so the menu can offer it the way it offers Cursor and Grok Bot: install the package, then launch the desktop entry it ships.

The mark is a trace rather than a download. T3 publishes no monochrome SVG — the app icon is a black rounded tile with the letters knocked out of it, and a tile flattens to a solid square once the menu recolors every path with the theme foreground. Tracing the lettermark out of that icon keeps the silhouette that actually reads.

The font is package-owned, so the glyph reaches a desktop through an omarchy-settings release rather than omarchy update. Until that release lands, a pulled checkout draws the entry with no icon.

🤖 Generated by Opus 5 in Claude Code.

(cherry picked from commit 260a729104)
(cherry picked from commit a863dc8555a51e62535f0edf28d4158d9d2e9fb4)

test/shell.d/menu-test.sh

@@ -514,5 +514,5 @@ assert(
 JS
 
 font_charset=$(fc-query --format='%{charset}' "$ROOT/default/fonts/omarchy/omarchy.ttf")
-[[ $font_charset == *"e900-e907"* ]] || fail "Omarchy icon font includes every custom menu glyph"
+[[ $font_charset == *"e900-e908"* ]] || fail "Omarchy icon font includes every custom menu glyph"
 pass "Omarchy icon font includes the official agent marks"