feat(design): every button on its family, the chip primitive, the lint rule (E28 S3b2)

The second half of the button sweep: the remaining hand-rolled buttons in
feature components, the design lab and the components/ui composites now
stand on Button, IconButton, Pressable, Chip or DragHandle.

- Chip + DismissibleChip (filter / token / tag / suggest / ghost, 24px
  floor, 44 on touch) replace five chip geometries; FilterChipGroup
  renders Chips; overflow lanes measure a mirror painted by chipClass.
- The Plex control row is IconButton's player rung (36, 20px glyph,
  round, overlay; 44 on touch); the YT modal bar is on the sm rung with
  pressed cycle toggles and names that survive a folded label.
- New variants: IconButton ghost-accent, danger-soft; Button warn on a
  new state-warn utility. The .btn-{tone} recipes and btnCls are gone.
- Fixed on the way: membership rows (collection editor, Plex playlist
  add) announce checked/mixed; a one-letter tag chip was 21px wide;
  descriptionLinks moved out of lib/ (it renders components).
- local/button-primitive: a raw <button>/<FocusSafeButton> outside the
  control-primitive files is a lint error (contract-tested, seen red).

frontend/src/components/LogLine.tsx

@@ -3,6 +3,7 @@ import type { ReactNode } from "react";
 import type { Level } from "../lib/log";
 import { navItemAttrs } from "../lib/listNav";
 import { LEVEL_TAG, logClock } from "./logLineParts";
+import { Pressable } from "./ui/Pressable";
 
 // One log line as both log viewers draw it — "Saját napló" (this tab's ring) and the admin
 // diagnostics console (the server's stored log): time, level, event code, message, and the line opens
@@ -39,13 +40,13 @@ export default function LogLine({
       className="border-b border-border/50 last:border-b-0"
       {...navItemAttrs(navIndex, `${event} ${msg}`)}
     >
-      <button
-        type="button"
+      <Pressable
+        layer={!open}
         data-nav-open
         aria-expanded={open}
         onClick={onToggle}
         title={title}
-        className={`grid w-full grid-cols-[6.5em_3.5em_minmax(0,1fr)] items-baseline sm:grid-cols-[6.5em_3.5em_minmax(0,10em)_minmax(0,1fr)] gap-x-2 px-3 py-1 text-left hover:bg-card ${
+        className={`grid w-full grid-cols-[6.5em_3.5em_minmax(0,1fr)] items-baseline sm:grid-cols-[6.5em_3.5em_minmax(0,10em)_minmax(0,1fr)] gap-x-2 px-3 py-1 ${
           open ? "bg-accent/10" : ""
         }`}
       >
@@ -55,7 +56,7 @@ export default function LogLine({
         {/* A phone has no room for a fourth column: the message takes a line of its own under the
             code, full width — sharing the code's line left it a few characters. */}
         <span className="col-span-3 truncate sm:col-span-1">{msg}</span>
-      </button>
+      </Pressable>
       {open && <div className="bg-accent/5 px-3 py-2 text-muted">{children}</div>}
     </div>
   );