[Bug]: [P3] The editor panel's gutted-unit warning ships a raw glyph that can tofu

Found by the Edge Case Hunter while reviewing the #782 guard widening. Pre-existing, and it sits in the blind spot of both icon guards.

The defect

src/ui/templates/editor.ts:136:

rows.push(kv("⚠", "Gutted: bulldoze and rebuild."));

That is a bare U+26A0 with no variation selector. Two things follow, and both are needed for the bug:

1. The guards cannot see it. EMOJI_SCAN matches \p{Emoji_Presentation} or \p{Emoji}\uFE0F. Probed: /\p{Emoji}/u.test("⚠") is true but /\p{Emoji_Presentation}/u.test("⚠") is false, and there is no VS16 here, so neither branch matches. The coverage guard (#721) and the message-leading guard (#743) both walk straight past it.
2. The mapper never runs on it anyway. kv renders its label as a plain lit text binding. The only callers of messageWithIcons/appendMessageWithIcons are src/ui/uiStatus.ts and src/ui/templates/eventChoice.ts, so the editor panel's key column is not an icon-swapping surface at all.

So the glyph reaches the DOM raw. On a system with no symbol coverage for U+26A0 (a bare Linux container, a stripped WSL image) the player sees tofu in the gutted-unit card. The identical warning written WITH the VS16 in src/game/appBoot.ts and src/game/desktopSaveHydrate.ts is swapped for the pixel warning icon correctly, which is what makes this inconsistent rather than merely unmapped.

Fix shape

Either render the icon directly (kv(iconTemplate("warning"), ...), matching how other non-message surfaces do it) or add the VS16 and route that row through the mapper. The first is preferable: the editor panel is not a message rail, and making it one to fix a glyph would be the larger change.

Worth considering alongside it

The guards' scan definition is the deeper gap. They are built around emoji-presentation characters, so any text-default symbol written without a VS16 is invisible to them by construction, and that is exactly the shape that tofus. Widening EMOJI_SCAN to catch bare \p{Emoji} would surface this class, at the cost of matching a lot of legitimate punctuation (©, ™, ‼, the digits). Not obviously worth it, but the tradeoff should be a decision rather than an accident.

Related: #721 (the mapping requirement), #743 (the message-leading requirement), #782 (the scope widening that surfaced this).

Start at src/ui/templates/editor.ts:136 and compare the row with the warning-icon rendering used by other non-message surfaces. Keep the editor panel out of the message mapper, and make the gutted-unit warning render without a raw glyph. Treat widening EMOJI_SCAN as a separate decision, since the issue identifies it as a broader tradeoff rather than a required part of this fix.