Webapp redesign: imaging floor at laptop widths, keyboard tips, placeholders

From the design review:
- Floor rows reserve 150px for actions instead of 190px; stage text is
  one line with the full text in a tip (safety text still wraps); the PC
  type hides first; rows stack only below 960px of panel width, with the
  actions on the status line instead of their own row.
- Tips also show on keyboard focus.
- Placeholders use the muted token (dark-theme contrast was 3.6:1).
- Save bar focus ring uses the save bar's accent (2.8:1 before).

webapp/static/pxe-ui.css

@@ -244,15 +244,17 @@ details.more .menu form { margin: 0; }
 .floor { container-type: inline-size; }
 .frow, .fhead {
   display: grid; grid-template-columns: 118px minmax(160px, 270px) minmax(0, 1fr);
-  grid-template-areas: "st pc stage"; align-items: center; gap: 0 20px; padding: 14px 230px 14px 24px;
+  grid-template-areas: "st pc stage"; align-items: center; gap: 0 20px; padding: 14px 176px 14px 24px;
 }
 .fhead { padding-top: 6px; padding-bottom: 6px; font-size: 12px; letter-spacing: .04em; text-transform: uppercase; color: var(--muted); }
 .g-st { grid-area: st; } .g-pc { grid-area: pc; min-width: 0; display: flex; flex-direction: column; } .g-stage { grid-area: stage; min-width: 0; }
-.floor-row .g-act { position: absolute; right: 20px; top: 16px; width: 190px; justify-content: flex-end; }
+.floor-row .g-act { position: absolute; right: 16px; top: 14px; width: 150px; justify-content: flex-end; }
 .floor-row .serial { font-size: 15px; }
 .stageline { display: flex; align-items: center; gap: 12px; font-size: 13px; min-height: 24px; }
-.stageline .txt { flex: 1 1 auto; min-width: 0; white-space: normal; }
+.stageline .txt { flex: 1 1 auto; min-width: 0; }
-.stageline .warnline { font-weight: 600; }
+.stageline .txt.tip > .trunc { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
+/* Safety text ("do not power off", erasing) is never truncated. */
+.stageline .warnline { font-weight: 600; white-space: normal; }
 .stageline .kind { flex: none; font-size: 12px; color: var(--muted); max-width: 40%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 .stageline .step { flex: none; color: var(--muted); font-size: 12px; }
 .fbody { display: flex; gap: 24px; align-items: flex-start; padding: 0 24px 16px 162px; font-size: 13px; }
@@ -264,12 +266,17 @@ details.more .menu form { margin: 0; }
 .floor-logs { border-top: 1px solid var(--line); }
 .floor-logs > summary { padding: 0 24px; min-height: 44px; color: var(--text-2); font-weight: 400; }
 .floor-empty { padding: 28px 24px; text-align: center; border-top: 1px solid var(--line); }
-@container (max-width: 820px) {
+@container (max-width: 1150px) { .stageline .kind { display: none; } }
+@container (max-width: 960px) {
   .fhead { display: none; }
-  .frow { grid-template-columns: auto minmax(0, 1fr); grid-template-areas: "st pc" "stage stage"; gap: 10px 14px; padding: 14px 18px; }
+  /* Stacked: status and PC on line one (actions sit at its right), stage below. */
-  .floor-row .g-act { position: static; width: auto; display: flex; justify-content: flex-end; padding: 0 18px 12px; }
+  .frow { grid-template-columns: auto minmax(0, 1fr) 150px; grid-template-areas: "st pc ." "stage stage stage"; gap: 10px 14px; padding: 14px 18px; }
+  .floor-row .g-act { right: 14px; top: 12px; }
   .fbody { padding: 0 18px 14px; flex-direction: column; }
 }
+@container (max-width: 560px) {
+  .frow { grid-template-columns: minmax(0, 1fr) 150px; grid-template-areas: "st ." "pc pc" "stage stage"; }
+}
 
 /* Overview image cards */
 .img-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(250px, 100%), 1fr)); gap: 16px; }
@@ -280,3 +287,14 @@ details.more .menu form { margin: 0; }
 
 /* The legacy .mono rule sets 13px; inside headings mono text keeps the heading size. */
 h1 .mono, h2 .mono, .ui-head h1 .mono { font-size: inherit; }
+
+/* Tips also show for keyboard focus (they stay a convenience: data they
+   carry is always in the row body too). */
+.tip[data-tip]:focus-within::after, summary:focus-visible .tip[data-tip]::after {
+  content: attr(data-tip); position: absolute; left: 0; top: calc(100% + 6px); z-index: 20;
+  width: max-content; max-width: min(440px, 80vw); white-space: normal;
+  background: var(--tip-bg); color: var(--tip-text); font: 400 12px/1.45 var(--font);
+  padding: 7px 10px; border-radius: 6px; box-shadow: 0 4px 14px rgba(0,0,0,.25); text-align: left;
+}
+.field::placeholder, .form-control::placeholder { color: var(--muted); opacity: 1; }
+.savebar :focus-visible { outline-color: var(--savebar-pri); }

webapp/templates/_imaging_tiles.html

@@ -107,7 +107,7 @@
         <span class="g-st">{{ ui.chip(state_chip[state][0], state_chip[state][1]) }}</span>
         <span class="g-pc"><span class="mono serial">{{ title }}</span><span class="sub">{{ ident | join(' | ') or ('MAC ' ~ s.mac if s.mac else '') }}</span></span>
         <span class="g-stage">
-          <span class="stageline"><span class="txt{{ ' warnline' if warn }}">{{ label }}</span>{% if kind %}<span class="kind">{{ kind }}</span>{% endif %}{% if not is_inferred %}<span class="mono step">{{ stage_idx }}/{{ stage_total or '?' }}</span>{% endif %}<span class="chev" aria-hidden="true">&#9662;</span></span>
+          <span class="stageline">{% if warn %}<span class="txt warnline">{{ label }}</span>{% else %}<span class="txt tip" data-tip="{{ label }}"><span class="trunc">{{ label }}</span></span>{% endif %}{% if kind %}<span class="kind">{{ kind }}</span>{% endif %}{% if not is_inferred %}<span class="mono step">{{ stage_idx }}/{{ stage_total or '?' }}</span>{% endif %}<span class="chev" aria-hidden="true">&#9662;</span></span>
           {% if not is_inferred and stage_total %}{{ ui.track(stage_total, stage_idx, track_kind.get(state, 'run'),
               label=('Done, all ' ~ stage_total ~ ' stages' if state == 'done' else 'Stage ' ~ stage_idx ~ ' of ' ~ stage_total)) }}{% endif %}
         </span>