ifcviewer-web: navigation parity — view all, XYZ views, ortho, zoom-to-selected

The camera math already lived in the shared ViewportCore; the desktop just
bound keys to it. The web build had no keyboard handler and no camera UI, so
none of it was reachable. Wire it up (Tier 1 + 2 of nav parity; fly mode is a
separate follow-up).

Shared core:
- setStandardView(StandardView) — named Front/Back/Left/Right/Top/Bottom wrapper
  over setStandardView(yaw,pitch), so the axis→angle mapping lives in one place.
- frameSelection() — lifts the desktop's "union selected AABBs → frameAabb(1.30)"
  focus logic out of ViewportWindow into the core. Desktop's focusOnSelectedObject
  and the X/Y/Z hotkeys now call these (DRY, behaviour unchanged).

Web:
- main_web gains a keydown handler matching the desktop bindings — Home=view all,
  F=zoom to selected, P=ortho toggle, X/Y/Z (+Shift=negative)=standard views —
  plus exported entry points (view_all_c / frame_selection_c / toggle_projection_c
  / projection_is_ortho_c / standard_view_c) for the toolbar.
- shell.html adds a bottom nav toolbar (Fit / Focus / Persp-Ortho / the six views)
  with the hotkeys in tooltips; the ortho button reflects state.

Verified: Z key and Front button both move the camera, ortho toggles render +
label, zero GPU errors; 111/111 unit + 6/6 web smoke pass.

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

src/ifcviewer/ViewportCore.cpp

@@ -445,6 +445,40 @@ void ViewportCore::setStandardView(float yaw_deg, float pitch_deg) {
     host_->requestFrame();
 }
 
+void ViewportCore::setStandardView(StandardView view) {
+    switch (view) {
+    case StandardView::Front:  setStandardView(0.0f,   0.0f);   break;
+    case StandardView::Back:   setStandardView(180.0f, 0.0f);   break;
+    case StandardView::Right:  setStandardView(90.0f,  0.0f);   break;
+    case StandardView::Left:   setStandardView(270.0f, 0.0f);   break;
+    case StandardView::Top:    setStandardView(camera_yaw_deg_,  90.0f); break;
+    case StandardView::Bottom: setStandardView(camera_yaw_deg_, -90.0f); break;
+    }
+}
+
+bool ViewportCore::frameSelection() {
+    if (selection_.count() == 0) return false;
+    float lo[3] = {  std::numeric_limits<float>::infinity(),
+                     std::numeric_limits<float>::infinity(),
+                     std::numeric_limits<float>::infinity() };
+    float hi[3] = { -std::numeric_limits<float>::infinity(),
+                    -std::numeric_limits<float>::infinity(),
+                    -std::numeric_limits<float>::infinity() };
+    bool any = false;
+    for (uint32_t id : selection_.selectionIds()) {
+        float mn[3], mx[3];
+        if (!computeObjectAabb(id, mn, mx)) continue;
+        for (int i = 0; i < 3; ++i) {
+            lo[i] = std::min(lo[i], mn[i]);
+            hi[i] = std::max(hi[i], mx[i]);
+        }
+        any = true;
+    }
+    if (!any) return false;
+    frameAabb(lo, hi, 1.30f);
+    return true;
+}
+
 void ViewportCore::orbitBy(float dx_px, float dy_px) {
     // 0.4 deg/px matches the GL viewport. pitch is clamped just shy of
     // the pole so orbitEye() stays well-conditioned.

src/ifcviewer/ViewportCore.h

@@ -185,6 +185,19 @@ public:
                    float dist, float yaw_deg, float pitch_deg);
     void setStandardView(float yaw_deg, float pitch_deg);
 
+    // Named axis-aligned views. Front/Back/Left/Right pin yaw at 0/180/270/90
+    // (pitch 0); Top/Bottom pin pitch at ±90° and keep the current yaw. Wraps
+    // setStandardView(yaw,pitch) so the mapping lives in one place (shared by
+    // the desktop hotkeys and the web toolbar/keys).
+    enum class StandardView { Front, Back, Left, Right, Top, Bottom };
+    void setStandardView(StandardView view);
+
+    // Frame the current selection: union the selected objects' world AABBs and
+    // fit the camera to them (same 1.30 padding as the desktop "F" hotkey).
+    // No-op with an empty selection or no resolvable AABBs; returns whether it
+    // framed anything. Uses the shared selection + computeObjectAabb/frameAabb.
+    bool frameSelection();
+
     // ---- Incremental orbit navigation ---------------------------------------
     //
     // Pixel-delta camera moves, shared by every host (Qt desktop + web).

src/ifcviewer/ViewportWindow.cpp

@@ -1519,31 +1519,10 @@ bool ViewportWindow::computeObjectAabb(uint32_t id,
 
 void ViewportWindow::focusOnSelectedObject() {
     if (fps_mode_) return;
-    if (selection_.count() == 0) {
-        Log::info() << "[wgpu] focus: no object selected";
-        return;
+    // Shared math lives in ViewportCore::frameSelection (also the web path).
+    if (!core_.frameSelection()) {
+        Log::info() << "[wgpu] focus: no object selected / no AABB available";
     }
-    float lo[3] = {  std::numeric_limits<float>::infinity(),
-                     std::numeric_limits<float>::infinity(),
-                     std::numeric_limits<float>::infinity() };
-    float hi[3] = { -std::numeric_limits<float>::infinity(),
-                    -std::numeric_limits<float>::infinity(),
-                    -std::numeric_limits<float>::infinity() };
-    bool any = false;
-    for (uint32_t id : selection_.selectionIds()) {
-        float mn[3], mx[3];
-        if (!computeObjectAabb(id, mn, mx)) continue;
-        for (int i = 0; i < 3; ++i) {
-            lo[i] = std::min(lo[i], mn[i]);
-            hi[i] = std::max(hi[i], mx[i]);
-        }
-        any = true;
-    }
-    if (!any) {
-        Log::info() << "[wgpu] focus: no AABB available";
-        return;
-    }
-    frameAabb(lo, hi, 1.30f);
 }
 
 // setStandardView / toggleProjection / cameraString moved to ViewportCore (#84-i).
@@ -2226,10 +2205,11 @@ void ViewportWindow::keyPressEvent(QKeyEvent* event) {
         && (mods == Qt::NoModifier || mods == Qt::ShiftModifier)
         && !event->isAutoRepeat()) {
         const bool neg = (mods & Qt::ShiftModifier);
+        using SV = ViewportCore::StandardView;
         switch (key) {
-        case Qt::Key_X: setStandardView(neg ? 180.0f : 0.0f,   0.0f); break;
-        case Qt::Key_Y: setStandardView(neg ? 270.0f : 90.0f,  0.0f); break;
-        case Qt::Key_Z: setStandardView(camera_yaw_deg_, neg ? -90.0f : 90.0f); break;
+        case Qt::Key_X: core_.setStandardView(neg ? SV::Back   : SV::Front); break;
+        case Qt::Key_Y: core_.setStandardView(neg ? SV::Left   : SV::Right); break;
+        case Qt::Key_Z: core_.setStandardView(neg ? SV::Bottom : SV::Top);   break;
         }
         return;
     }