Explain the eyedropper for object variables (#276)

Behaviors gets a point after picking a target from the dropdown. Keyboard lists Enter and Esc while the eyedropper runs. Development counts 1596 e2e checks.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Behaviors.md

@@ -66,6 +66,18 @@ playing use the same two words.
     object itself included. The pick is stored as the object's id, `{"$object": "<id>"}`, and a run
     reads the object itself. On the behavior asset there is no scene, so the row says `(null)` and
     offers nothing; the default is always no object.
+  - **The eyedropper** beside the dropdown picks in the view instead (#276). It brings up the scene
+    view, or the tab of the container the object sits in, with a bar over it
+    (`Target for <object> · <field>: <candidate>  [Take] [Cancel]`) and a crosshair. A click only
+    makes a candidate, outlined in its own colour, and the object with the variable stays selected.
+    It follows the selection rule: a click on the candidate passes on to the object behind it,
+    round to the front again, and a click elsewhere takes the one in front there. Empty space keeps
+    the candidate, and so does a spot with nothing the dropdown offers, with a notice why.
+    **Enter** or *Take* writes it as one undo step (none when it is the target already).
+    **Escape**, *Cancel*, a right-click in the view or a second press of the eyedropper leave the
+    place as it was. Started from a Variables tab, it goes back there afterwards. Another tab,
+    another selection, undo, redo or Play end it without writing. While it runs the view does
+    nothing else (no dragging, marquee, brush, handles or menu); panning and zooming still work.
   - **Inside a container** an object only gets the objects of the same container to choose from,
     named by their template id. Every placement of the container then reaches its own copy.
   - **The reference follows the object:** removing it empties the reference in the same undo step,

Development.md

@@ -18,7 +18,7 @@ php tests/php/accounts.test.php                               # the API's accoun
                                                               #   has and the web server's container has not (SKIP there)
 php tests/php/snapshots.test.php                              # the snapshot store (#231), the same way
 php tests/php/releases.test.php                               # the release store (#266), the same way
-node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1591 editor checks, screenshots in /tmp/gm-e2e-*.png
+node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1596 editor checks, screenshots in /tmp/gm-e2e-*.png
 GM_STEPS=20 node tools/e2e.mjs                                # or 1-12, or 6,20 — a subset while working on one step
 ./e2e.sh start [GM_STEPS]                                     # the same run detached, see below
 ./e2e.sh status                                               # live progress, or the last run's result

Keyboard.md

@@ -2,6 +2,8 @@
 `Backspace` remove the selection (objects, nodes, frames, the shapes of a vector art, keys or a row of the Animation tab, a graph group or comment — the box only, its nodes stay, and a band that caught boxes and nodes together removes both in one step; an asset asks first) · `Ctrl+G` create
 container from the selection · `Ctrl+Enter` play, and pause/resume while playing · `Esc` stop ·
 `Esc` on a question does what its Cancel does ·
+while the eyedropper of an object variable picks, `Enter` takes the candidate and `Esc` leaves
+without it, before anything else those keys do ([Behaviors](Behaviors)) ·
 `Ctrl+C` copy the selected objects or graph nodes, `Ctrl+V` paste them
 under the pointer ([Scene editing](Scene-editing), [Behaviors](Behaviors)) · `Ctrl+V` import an image from
 the clipboard as a texture when nothing copied fits the tab (ignored while a text field has focus) · Animation tab: `Ctrl+C` copy