Describe the clickable collider symbol in the scene view

Colliders.md

@@ -15,7 +15,7 @@ goes into this placement's overrides, so other sprites wearing the same collider
 value equal to the asset's own clears the override instead. The collider's own scale is divided
 out, a collider turned by a quarter swaps width and height, and a circle takes the radius that fits
 inside. A polygon or frame outline has no size to fit, and a collider that does not sit on a
-sprite has nothing to fit to: the entry is greyed out for both. They are editor symbols: green outlines in edit mode, invisible in play mode. Three more rows —
+sprite has nothing to fit to: the entry is greyed out for both. They are editor symbols: green outlines in edit mode, invisible in play mode. Like every other symbol a collider also has an icon, in the colour of its outline (green, the trigger colour, or red for a shape that collides with nothing). It stands just left of the collider's centre, stays upright and unscaled, and a click on it selects the collider, just like a click on its outline. The middle of the sprite stays free: a click there, or anywhere else inside the outline, still reaches the sprite the collider sits on. A rigidbody's icon on the same centre stays uncovered too, with its name to its right. Three more rows —
 friction, bounciness, density — are the material a rigidbody feels (see [Physics](Physics)).
 
 A collider takes the transform of its body: a box turns and grows with the sprite it sits on, a

Development.md

@@ -14,7 +14,7 @@ npm run build        # writes dist/ and regenerates index.html
 ./build.sh           # the same under `set -o pipefail`, for callers that pipe the output
 php tools/make-user.php <name> <password> [admin|user]        # an account; every tool signs in (see Accounts)
 php tests/php/accounts.test.php                               # the API's account rules, no server needed (CI's gate job)
-node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1348 editor checks, screenshots in /tmp/gm-e2e-*.png
+node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1351 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

Scene-editing.md

@@ -16,8 +16,8 @@ constant size on screen however far you zoom, and both kinds of them — the obj
 Scene tab and the frame names of the Texture tab — read that size from one token
 (`Theme.viewportLabelSize`); the two `viewportLabel` styles differ in colour only.
 
-**The symbol icons are SVG files** (#175): behavior, container, rigidbody, camera and particle
-source each have one in `src/viewport/icons/`, bundled with the editor and parsed once. A file
+**The symbol icons are SVG files** (#175): behavior, container, rigidbody, collider, camera and
+particle source each have one in `src/viewport/icons/`, bundled with the editor and parsed once. A file
 draws in the symbol's own units with the origin at its centre (the `viewBox` is centred on it, so
 the file looks the same in any SVG viewer), and `currentColor` stands for the colour the theme
 gives that symbol. To change an icon, edit its file and build. Pixi's SVG parser is not a browser,