fix(menu): #131 — size text menus in ch with a cap, not in % of the monitor

Bernardo saw Recovery ellipsize on a 2560x1440 external, which falsified
the item's model (40% + Inter 11 → "only below 1920"). Real cause: text
menus render through themes/<slug>/rofi.rasi, where boreal + neon-glass
pinned width: 620px (fixed — a wide panel buys nothing) while seven used
40%, and the font is whatever that file says — mostly monospace, far
wider than the Inter that was measured. The modelled combination ships in
no theme.

The insight: a menu must fit its longest label, which is a count of
characters in the THEME's font — so the window must scale with the font,
not the screen. 40% gives a 1366 panel 546px and a 2560 one 1024px for
the same row, and a 14pt mono theme needs ~25% more room than an 11pt one
on both; a percentage cannot see either fact.

Rofi has the right unit (`ch` = width of one digit in the current font)
and `calc( a min b )` to cap it, so every text menu — generated and all
nine whole-swaps — is now `width: calc( 84ch min 65% )`. 84ch fits the
longest row we ship (69 chars) plus icon and padding; the cap is
Bernardo's condition (never sprawl on a low-res panel) and it is
measured, not assumed.

Verified on hardware, not by arithmetic: 84ch = 756px in GeistMono 11 and
924px in JetBrainsMono 14; `calc( 84ch min 300px )` → 300px, so the clamp
really clamps. Screenshots at both ends — the real Recovery menu at 756px
(29% of 2560) with every label complete, and the Acer worst case
reproduced pixel-exactly (888px = 65% of 1366, JetBrainsMono 14) also
complete. Grid views override width per-invocation and are untouched.
checks.rofi-text-width guards the class, proven by pinning boreal back to
620px and watching it fail by name. Acer V3 queued for its own fontconfig.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

modules/home/rofi.nix

@@ -1805,7 +1805,20 @@ in
             border = px t.ui.borderSize;
             border-color = mkLiteral "@accent";
             border-radius = px t.ui.rounding;
-            width = mkLiteral "40%";
+            # Sized in `ch` — the width of one digit in *this theme's* font —
+            # not in % of the monitor (#131). A menu has to fit its longest
+            # label, and that is a count of characters, so the window must
+            # scale with the font: 40% of a 1366 panel and 40% of a 2560 one
+            # give the same row 546px and 1024px, while a 14pt monospace theme
+            # needs ~25% more room than an 11pt one on both. 84ch fits the
+            # longest row we ship (69 chars) plus icon and padding, measured on
+            # hardware: 756px in GeistMono 11, 924px in JetBrainsMono 14.
+            # The `min` cap is what keeps that honest on a small screen — the
+            # window may never eat more than 65% of the panel, so a big font on
+            # a 1366 gets a capped 888px rather than sprawling. Grid views
+            # (theme picker, drun) override this per-invocation; they are sized
+            # by icons, not text.
+            width = mkLiteral "calc( 84ch min 65% )";
             padding = px 8;
           };