Lataa WinTUI 2.7.3

- Cleanup tab now fits short terminals. The previous renderer drew every group panel at its natural height with no viewport, so any terminal shorter than the total group stack clipped the bottom panels off-screen — visible immediately after the new WinTUI group landed as a fifth panel. The renderer now lays out every group into a single line buffer and slides a window over it so the focused row is always visible. The selected-summary counter now also counts every checked row instead of only rows with non-zero scanned size, so "5 selected, 0 B" tells the user immediately that picked rows scanned empty.
- New WinTUI cleanup group. Adds a fifth Cleanup group with two glob-mode targets rooted at %LOCALAPPDATA%\wintui\self-update\: the unbounded wintui-self-update.log (the only WinTUI-owned file that grows monotonically) and handoff-*.ps1 scripts with a 24h minAge floor. Both default-unchecked, no new admin surface.
- Subtle gray tier across screens. The palette had two tiers (bright for primary text, dim for chrome) and dim was carrying six different roles, so versions, free GB, and package IDs read as background. Adds a third "subtle" tier for meaningful-but-not-headline data; applied to Settings choice chips, Health right-column detail, Workspace version columns, and the package ID under the summary detail title. Pink stays reserved for structural focus.
- Toolchain bump: Go 1.26.1 → 1.26.3 (11 stdlib security fixes). Charm: bubbletea 2.0.2 → 2.0.6, lipgloss 2.0.2 → 2.0.3, runewidth 0.0.21 → 0.0.23. golang.org/x/sys 0.42.0 → 0.44.0. Static-surface check vs the pre-bump tree: zero new syscall/windows symbols, four removed.
- No bugfixes, no breaking changes, no new Win32 surface. Settings.json and cache.json formats are unchanged.