Editor: dynamic input bounds + full hierarchy validation, layout polish

Bounds (new src/editor/bounds.js):
- Sets HTML5 min/max on every level + percent input each redraw,
  derived from the current values of related inputs so the spinner
  stops at the basin hierarchy:
  0 < outflowLevel < dryRunLevel < startLevel ≤ inflowLevel
      ≤ shiftLevel ≤ maxLevel ≤ overflowLevel ≤ basinHeight
- dryRunPercent capped so dryRunLevel ≤ startLevel given current outflow.
- shiftArmPercent ∈ [1, 100]; highVolumeSafety% ∈ [1, 100].

Validation:
- New visible ribbon above the basin diagram (#ps-basin-validation)
  listing every hierarchy violation. The in-SVG warning text is now a
  small reminder ("⚠ N ordering issues").
- basin-diagram.js owns hierarchy issues; mode-preview.js trimmed to
  only own shift-specific issues (shift > start, shift ≤ max,
  shiftArmPercent range, shiftLevel required-when-enabled).
- oneditsave blocks Deploy on the union of _psBasinValidationIssues
  and _psModeValidationIssues with a RED.notify listing all problems.

Layout polish:
- Side panel widened to 220 px with minmax(0, 1fr) first column so long
  labels can no longer push the rows past the panel edge.
- Basin SVG max-width 380 → 360, gap between side panel and SVG bumped
  14 → 28 px. Tank shifted right (x=145 width=110) so the inlet
  "bottom of pipe" sub-label is no longer clipped on the left edge.
- "0 m (datum)" moved below the tank (y=395, centred) so it can't
  collide with "Outlet / top of pipe" when outflowLevel is near floor.
- Zone labels shortened (Spare / Sewage + buffer / Buffer / Dead vol)
  and only show when the bracketing thresholds are ≥ 28 px apart, so
  they never sit on a threshold label.
- Mode preview axis labels under the chart removed — line colour +
  side-panel labels + hover-couple already identify each line. Stub
  <text> elements left hidden to keep the redraw loop simple. Arm-%
  line + label trimmed in 10 px on the right so they're not clipped.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/editor/mode-preview.js

@@ -146,7 +146,9 @@
         }
       }
 
-      // Vertical level markers + axis labels.
+      // Vertical level markers — line only. Axis labels were removed;
+      // identification comes from line colour + side-panel labels +
+      // hover coupling.
       [
         ['dryRunLevel', dryRun],
         ['startLevel', start],
@@ -155,18 +157,14 @@
         ['overflowLevel', overflow],
       ].forEach(([id, level]) => {
         const line = document.getElementById(`ps-mode-line-${id}`);
-        const label = document.getElementById(`ps-mode-label-${id}`);
-        if (!line || !label) return;
+        if (!line) return;
         if (!Number.isFinite(level)) {
           line.style.display = 'none';
-          label.style.display = 'none';
           return;
         }
         const x = xFor(level);
         line.style.display = '';
-        label.style.display = '';
         line.setAttribute('x1', x); line.setAttribute('x2', x);
-        label.setAttribute('x', x);
       });
 
       // Background zone bands.
@@ -192,19 +190,15 @@
       setBand('ps-zone-safetyHigh', xMax,  xOvf);
       setBand('ps-zone-overflow',   xOvf,  plotR);
 
-      // Shift level marker.
+      // Shift level marker (line only).
       const shiftLine = document.getElementById('ps-mode-line-shiftLevel');
-      const shiftLabel = document.getElementById('ps-mode-label-shiftLevel');
-      if (shiftLine && shiftLabel) {
+      if (shiftLine) {
         if (shiftEnabled && Number.isFinite(shift)) {
           const x = xFor(shift);
           shiftLine.setAttribute('x1', x); shiftLine.setAttribute('x2', x);
-          shiftLabel.setAttribute('x', x);
           shiftLine.style.display = '';
-          shiftLabel.style.display = '';
         } else {
           shiftLine.style.display = 'none';
-          shiftLabel.style.display = 'none';
         }
       }
 
@@ -237,16 +231,11 @@
         }
       }
 
-      // Validation: ordering constraints.
+      // Validation: only mode-specific (shift) ordering. Basin-level
+      // hierarchy (start ≤ inlet ≤ max ≤ overflow ≤ basinHeight,
+      // dryRun < start) is owned by basin-diagram.js so it shows in the
+      // basin section near the offending inputs.
       const issues = [];
-      if (Number.isFinite(dryRun) && Number.isFinite(start) && dryRun >= start)
-        issues.push('dryRunLevel (derived) must be < startLevel — increase startLevel or lower dryRun%');
-      if (Number.isFinite(start) && Number.isFinite(inlet) && start >= inlet)
-        issues.push('startLevel must be < inflowLevel (set in basin above)');
-      if (Number.isFinite(inlet) && Number.isFinite(max) && inlet >= max)
-        issues.push('inflowLevel must be < maxLevel');
-      if (Number.isFinite(max) && Number.isFinite(overflow) && max > overflow)
-        issues.push('maxLevel must be ≤ overflowLevel');
       if (shiftEnabled) {
         const shiftVal = Number(shiftInput?.value);
         if (Number.isFinite(shiftVal)) {