Alias navigation preset uses Shift+Alt with LMB/MMB/RMB (Fixes #304) (#306)

Navigation presets are now a table of bindings (button, required modifier
keys, camera mode) instead of string matches. The Alias preset binds
Shift+Alt+left to orbit, Shift+Alt+middle to pan and Shift+Alt+right to
zoom. A left press with a binding's keys is latched until release, so that
drag neither box-selects nor drags sketch geometry; plain left drags behave
as before. Shift only requests snapping when the binding without Shift
still orbits.

The scenario harness sends Alt with ui.drag/ui.click, and camera checks can
assert panned/zoomed since the last camera step. The user guide notes Alt+drag
grabs by KDE and GNOME and how to free them.


Claude-Session: https://claude.ai/code/session_01RjGw4gA5ZvKrU8MQP6sBgT

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

crates/ui-egui/tests/scenarios/alias_navigation_bindings.json

@@ -0,0 +1,30 @@
+[
+  {"note": "Alias preset (#304): Shift+Alt+left drag orbits, Shift+Alt+middle pans, Shift+Alt+right zooms (down: out, up: in). Other presets don't navigate with Shift+Alt+left."},
+  {"call": "engine.execute", "params": {"command": "solid.box", "params": {"length": 20, "width": 10, "height": 5}}},
+  {"call": "ui.prefs", "params": {"nav": "alias"}},
+  {"expect": {"prefs": {"nav": "alias"}}},
+
+  {"note": "Orbit: like a right drag (from the drag threshold on), and Shift (part of the binding) doesn't snap."},
+  {"camera": {"yaw": 0, "pitch": 0}},
+  {"call": "ui.drag", "params": {"x0": 800, "y0": 500, "x1": 848, "y1": 500, "steps": 8, "shift": true, "alt": true}},
+  {"expect": {"camera": {"yaw_deg": 19.25, "pitch_deg": 0, "panned": false, "zoomed": "no"}, "selection": 0}},
+
+  {"note": "Pan."},
+  {"camera": {"yaw": 0, "pitch": 0}},
+  {"call": "ui.drag", "params": {"x0": 800, "y0": 500, "x1": 860, "y1": 540, "steps": 8, "shift": true, "alt": true, "button": "middle"}},
+  {"expect": {"camera": {"yaw_deg": 0, "pitch_deg": 0, "panned": true, "zoomed": "no"}}},
+
+  {"note": "Zoom (dolly): dragging down moves away, dragging up moves closer."},
+  {"camera": {"yaw": 0, "pitch": 0}},
+  {"call": "ui.drag", "params": {"x0": 800, "y0": 500, "x1": 800, "y1": 560, "steps": 8, "shift": true, "alt": true, "button": "right"}},
+  {"expect": {"camera": {"yaw_deg": 0, "pitch_deg": 0, "panned": false, "zoomed": "out"}, "dialog": null}},
+  {"camera": {"yaw": 0, "pitch": 0}},
+  {"call": "ui.drag", "params": {"x0": 800, "y0": 500, "x1": 800, "y1": 440, "steps": 8, "shift": true, "alt": true, "button": "right"}},
+  {"expect": {"camera": {"yaw_deg": 0, "pitch_deg": 0, "panned": false, "zoomed": "in"}}},
+
+  {"note": "Fusion: Shift+Alt+left drag is not navigation."},
+  {"call": "ui.prefs", "params": {"nav": "fusion"}},
+  {"camera": {"yaw": 0, "pitch": 0}},
+  {"call": "ui.drag", "params": {"x0": 800, "y0": 500, "x1": 848, "y1": 500, "steps": 8, "shift": true, "alt": true}},
+  {"expect": {"camera": {"yaw_deg": 0, "pitch_deg": 0, "panned": false, "zoomed": "no"}}}
+]

crates/ui-egui/tests/scenarios/alias_plain_drag_box_selects.json

@@ -0,0 +1,16 @@
+[
+  {"note": "Alias preset (#304): a plain left drag still box-selects sketch geometry; the same drag with Shift+Alt orbits and selects nothing."},
+  {"call": "ui.prefs", "params": {"nav": "alias"}},
+  {"start": "sketch.create"},
+  {"click": {"plane": "XY"}},
+  {"call": "engine.execute", "params": {"command": "sketch.line", "params": {"points": [[10, 10], [30, 10]]}}},
+  {"call": "ui.view", "params": {"view": "top"}},
+  {"expect": {"camera": {"yaw_deg": 0, "pitch_deg": 90}}},
+  {"drag": [{"sketch": [5, 4]}, {"sketch": [40, 20]}], "steps": 10},
+  {"debug": 1},
+  {"expect": {"selection": 3, "camera": {"yaw_deg": 0, "pitch_deg": 90}}},
+  {"key": "Escape"},
+  {"expect": {"selection": 0}},
+  {"drag": [{"sketch": [5, 4]}, {"sketch": [40, 20]}], "steps": 10, "shift": true, "alt": true},
+  {"expect": {"selection": 0, "sketching": true}}
+]