merge(vt): plain <menu> style from latest-main-sync into slice7 panel work

Brings cfa703065's owner-driven fix (plugin <menu> renders VTank's plain
flat combo by default; style="retail" opts back into the gold pushbutton
art) into the S7.1-S7.3 window/tabs work so the fix round below can build
on both. Resolved conflicts: the ledger keeps both worktrees' entries in
chronological order (07:55/08:05 owner-read entries appended after this
worktree's own S7.1/S7.2/S7.3 entries); plugin-ui-markup.md's <menu> row
lists both new attributes (scroll, style); MarkupDocumentTests.cs keeps
both new test blocks (slider min/max + menu scroll from this worktree,
menu style from latest-main-sync).

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

docs/plans/2026-09-07-campaign-vt-slice7-tabs.md

@@ -126,3 +126,6 @@ re-review, merge to the campaign branch, then the owner's visual gate.
   this sub-slice's scope. Screenshots NOT captured (same ACE-down
   reason as S7.1/S7.2). Owner's visual gate against a running VTank is
   still owed for both S7.1/S7.2 and S7.3.
+- 2026-09-07 07:55 live screenshots of `89a49836c` captured (gate worktree, ACE up — the earlier "ACE down" was a TCP probe against a UDP server) → `docs/research/2026-09-07-slice7-screenshots/` (cropped to the panel, 864×360). Lead's read for the review + fix round: (1) Vitals reads like VTank; (2) Options has the right arrangement but VTank's literal `L,T,W,H` do not fit our DAT font — captions overlap the next row ("Follow/Nav Min Distance" over "Enable Navigation"): scale VTank's geometry to our font (row pitch from the DAT font's line height instead of VVS's 16 px; widths likewise), keep the proportions, never pixel-match; (3) Profiles still shows legacy controls (three stacked "New" buttons, the Loot engine row, the macro-profile path string drawn twice) — delete them; (4) the window is 856×350 with ~180 px of dead space below the content: bring the main panel back to VTank's 210-tall proportion (scaled) and make Advanced Options / Loot Editor their own plugin panels (separate windows, like VTank's popups) instead of in-panel groups; (5) the Route, Meta and Loot-editor pages show blank trailing button slots.
+- 2026-09-07 08:05 owner looked at the live gate build: (a) "The Options tab labels overlap, fix that"; (b) "Those BIG gold/yellow buttons HAS to go. That is not how vtank looks." — the plugin `<menu>` renders retail's gold pushbutton art; VTank's combos are plain (flat dark box, thin border, value text, small arrow at right — the same look as its lists). Fix round: plugin-markup `<menu>` draws the plain combo by default (a `style="retail"` opt-in keeps the gold art for anyone who wants it), plus the geometry scaling, the Profiles leftovers, the 210-tall main window and the two popups as separate panels.
+- 2026-09-07 09:10 S7.3 Monsters landed on the panel worktree (`57ced0aff`, `c3b4f7862`; MossTank suite 645 → 651) — same commits as the entry above; recorded again here because the plain-menu-style branch (`cfa703065`) merged into the panel worktree afterward to pick up fix (b) before fix round A started. Fix round A (grid scaling, Profiles leftovers, 260-tall window, Advanced Options / Loot Editor as their own panels, blank trailing slots, fresh screenshots) dispatched on the same worktree after merging the plain-menu style in. S7.4–S7.6 follow.

docs/plugin-ui-markup.md

@@ -108,9 +108,17 @@ vanishing from the built tree.
 | `toggle` | Lamp-style checkbox | `x y w h text checked onclick color` |
 | `slider` | Horizontal scalar | `x y w h value onchange min max` |
 | `field` | Single-line editable text | `x y w h text maxlength clearonsubmit onchange onsubmit color background` |
-| `menu` | Dropdown selector | `x y w h items selected onchange rows rowheight openupward scroll` |
+| `menu` | Dropdown selector | `x y w h items selected onchange rows rowheight openupward scroll style` |
 | `list` | Scrollable row list (+ Slice B icon column, + Campaign VT slice 1 multi-column) | `x y w h selected onchange rowheight` + either the single-column `items colors icons iconkind`, or one-to-many `<column>` children (see "Columns" below) — never both |
 
+`menu style` is `plain` (the default) or `retail`: retail's gold pushbutton
+art read as an out-of-place "big yellow button" next to a plugin's own dark
+list boxes (owner live-client report, 2026-09-07), so a plugin `<menu>` now
+draws the flat VTank/Decal `HudCombo` box (list-matching fill/border, a
+left-aligned value, and a small ▾) by default; `style="retail"` opts back
+into the gold face for a panel that genuinely wants it. Any other value
+throws `FormatException` at `Build`.
+
 Common to every element via `ApplyCommon`: `name`/`id` (a stable control
 name), `visible` (literal `true`/`false` or a bound `bool` property),
 `enabled` (same rule), and `tooltip` (a literal string or `{Binding}` shown