feat(theme-studio): inline height control on the exposed face rows

A new size column in the UI and package tables carries one numeric field plus an abs/rel toggle, exposed per the editable-height spec: chrome faces (mode-line family, line-number family, and header-line/tab-bar/tab-line when they arrive) default to absolute 1/10pt entry with a computed pt hint; the seeded heading faces (org-level-*, document title/info, agenda structure/dates, shr headings, and friends) default to a relative multiplier. Any other face carrying a live height exposes the control dynamically; the long tail gets none.

Absolute entry takes a positive integer only; relative entry clamps into the 0.1-2.0 range the old field used; garbage never reaches the model. The toggle writes heightMode explicitly and clears the number on a flip, since 130 tenth-points and 1.3x mean different things. The kind-unaware height field in the row expander is retired, and a non-default height now marks the size cell instead of the expander toggle.

The seeded set is named statically in app-core.js because the per-row default comes from the captured Emacs snapshot, which carries no heights for those faces. The #preview screenshot hash now accepts @ui/@code view keys so the harness can shoot the UI table.

1 files changed, 82 insertions, 5 deletions

diff --git a/scripts/theme-studio/test-app-core.mjs b/scripts/theme-studio/test-app-core.mjs
index c6e6650b..29c43abd 100644
--- a/scripts/theme-studio/test-app-core.mjs
+++ b/scripts/theme-studio/test-app-core.mjs
@@ -11,7 +11,7 @@ import {
   clearPalettePlan, deletePaletteColumnPlan, groundColumnMembersFromPalette, areAllLocked, lockToggleLabel, toggleLockSet,
   galleryModel, appViewKeysSorted, faceBoxNonDefaults, overflowNonDefault, stepViewIndex,
   cssWeight, faceDecoration, boxCss, faceCss, composeHoverTitle,
-  clampHeight, HEIGHT_MIN, HEIGHT_MAX,
+  clampHeight, HEIGHT_MIN, HEIGHT_MAX, heightControlKind, parseHeightEntry, ptHint,
 } from './app-core.js';
 import { planPaletteGenerator, entriesForGeneratedColumn } from './palette-generator-core.js';
 import { oklch2hex, deltaE } from './colormath.js';
@@ -1014,12 +1014,89 @@ test('overflowNonDefault: Boundary — matching attrs and in-row attrs do not fl
   assert.equal(overflowNonDefault({ weight: 'bold', slant: 'italic', strike: { color: null } }, {}, false), false);
 });
 
-test('overflowNonDefault: Boundary — inherit/height only count when shown in the expander', () => {
-  // packages keep inherit/height inline (showInheritHeight false) -> not flagged here
+test('overflowNonDefault: Boundary — inherit only counts when shown in the expander', () => {
   assert.equal(overflowNonDefault({ inherit: 'shadow', height: 1.4 }, {}, false), false);
-  // ui/syntax expose them in the expander (showInheritHeight true) -> flagged
+  // ui/syntax expose inherit in the expander (showInherit true) -> flagged
   assert.equal(overflowNonDefault({ inherit: 'shadow' }, {}, true), true);
-  assert.equal(overflowNonDefault({ height: 1.4 }, {}, true), true);
+  // height has its own inline cell now; it never flags the expander toggle
+  assert.equal(overflowNonDefault({ height: 1.4 }, {}, true), false);
+});
+
+// --- height control exposure + entry ----------------------------------------
+
+test('heightControlKind: Normal — chrome faces expose an absolute control', () => {
+  for (const f of ['mode-line', 'mode-line-inactive', 'header-line', 'tab-bar',
+                   'tab-line', 'line-number', 'line-number-current-line']) {
+    assert.equal(heightControlKind(f, {}, {}), 'abs', f);
+  }
+});
+
+test('heightControlKind: Normal — the seeded text faces expose a relative control statically', () => {
+  // the row default comes from the Emacs snapshot (no heights there), so the
+  // seeded set is named, not derived — bare cur/def must still expose
+  for (const f of ['org-level-1', 'org-level-5', 'org-document-title', 'shr-sup',
+                   'lsp-details-face', 'dashboard-banner-logo-title']) {
+    assert.equal(heightControlKind(f, {}, {}), 'rel', f);
+  }
+});
+
+test('heightControlKind: Normal — a face carrying a height exposes a relative control', () => {
+  assert.equal(heightControlKind('org-level-1', { height: 1.3 }, { height: 1.3 }), 'rel');
+  // the seed default alone is enough (the user may have cleared the live value)
+  assert.equal(heightControlKind('shr-h1', { height: 1 }, { height: 1.4 }), 'rel');
+  // a live height alone is enough (user-set on a face with no seed)
+  assert.equal(heightControlKind('embark-verbose-indicator-title', { height: 1.1 }, {}), 'rel');
+});
+
+test('heightControlKind: Normal — an explicit heightMode on the face wins', () => {
+  assert.equal(heightControlKind('mode-line', { heightMode: 'rel' }, {}), 'rel');
+  assert.equal(heightControlKind('org-level-1', { height: 2, heightMode: 'abs' }, {}), 'abs');
+});
+
+test('heightControlKind: Boundary — the long tail gets no control', () => {
+  assert.equal(heightControlKind('region', {}, {}), null);
+  assert.equal(heightControlKind('org-todo', { height: 1 }, { height: 1 }), null);
+  assert.equal(heightControlKind('cursor', null, null), null);
+});
+
+test('parseHeightEntry: Normal — absolute takes a positive integer', () => {
+  assert.equal(parseHeightEntry('abs', '130'), 130);
+  assert.equal(parseHeightEntry('abs', ' 90 '), 90);
+});
+
+test('parseHeightEntry: Error — absolute rejects floats, zero, negatives, garbage', () => {
+  for (const bad of ['1.3', '0', '-5', '13pt', 'big', '1e3']) {
+    assert.equal(parseHeightEntry('abs', bad), undefined, bad);
+  }
+});
+
+test('parseHeightEntry: Normal — relative takes a positive float, clamped into range', () => {
+  assert.equal(parseHeightEntry('rel', '1.2'), 1.2);
+  assert.equal(parseHeightEntry('rel', '5'), HEIGHT_MAX);
+  assert.equal(parseHeightEntry('rel', '0.05'), HEIGHT_MIN);
+  assert.equal(parseHeightEntry('rel', '.8'), 0.8);
+});
+
+test('parseHeightEntry: Error — relative rejects zero, negatives, garbage', () => {
+  for (const bad of ['0', '-1.2', '1.2x', 'big', '1.2.3']) {
+    assert.equal(parseHeightEntry('rel', bad), undefined, bad);
+  }
+});
+
+test('parseHeightEntry: Boundary — blank unsets (null) under either kind', () => {
+  assert.equal(parseHeightEntry('abs', ''), null);
+  assert.equal(parseHeightEntry('rel', '   '), null);
+  assert.equal(parseHeightEntry('rel', null), null);
+});
+
+test('ptHint: Normal — an absolute 1/10pt value renders as a pt hint', () => {
+  assert.equal(ptHint(130), '= 13.0pt');
+  assert.equal(ptHint(85), '= 8.5pt');
+});
+
+test('ptHint: Boundary — no number, no hint', () => {
+  assert.equal(ptHint(null), '');
+  assert.equal(ptHint(undefined), '');
 });
 test('faceBoxNonDefaults: inherit and box differences are flagged', () => {
   assert.equal(faceBoxNonDefaults({ inherit: 'bold' }, { inherit: null }).inherit, true);