M5: overlay positions relative to the layer that opens them

From the Figma forum request "Set overlay position relative to element,
not to page": an open overlay action takes anchor: screen (default) |
triggerInside | triggerOutside. With a trigger anchor the position preset
is measured on the layer that opens the overlay instead of the screen.
Outside puts top presets above it and bottom presets below it with the
edges lined up (a dropdown is Bottom left + Outside); Center centres it
on that layer. Manual is unchanged.

The interaction editor gets Relative to (Whole screen / Trigger layer)
and Inside / Outside. The player, the command (and so MCP and the
control channel) carry it; the command's params doc lists it. Figma has
no such setting, so .fig export writes it as a manual offset. Old files
and JSON without anchor read as screen and write unchanged.

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

docs/mcp.md

@@ -640,7 +640,11 @@ the scroll position with `preserveScroll: true`; `{type: "scrollTo", dest, offse
 the layer that far from the top-left of the innermost frame scrolling it, e.g. below a fixed
 header; `delayMs` makes a mouse enter, leave, down or up trigger wait before it acts;
 `{type: "openOverlay", dest, position: "manual", offset?: [x, y]}` puts the overlay that far from
-the top-left of the layer that opens it, and right below that layer without an offset). A key trigger takes a key or a combination (`{type: "keyPress", key: "Shift+K"}`; Ctrl,
+the top-left of the layer that opens it, and right below that layer without an offset;
+`anchor: "triggerInside" | "triggerOutside"` measures any other position on the layer that opens
+the overlay instead of the screen, so `{position: "bottomLeft", anchor: "triggerOutside"}` opens a
+dropdown right under its button, left edges lined up; Figma has no such setting, and `.fig` export
+writes it as a manual offset). A key trigger takes a key or a combination (`{type: "keyPress", key: "Shift+K"}`; Ctrl,
 Alt, Shift and Cmd, all held and no others) or a controller button (`key: "Gamepad A"`; `Gamepad`
 followed by `A`, `B`, `X`, `Y`, `LB`, `RB`, `LT`, `RT`, `View`, `Menu`, `LS`, `RS`, `Up`, `Down`,
 `Left`, `Right` or `Home`: the standard layout, face buttons by position), which the player reads

docs/prototyping-parity.md

@@ -1,6 +1,6 @@
 # Prototyping parity
 
-> **Last reviewed:** 2026-10-11 · **Last updated:** 2026-10-23 · **Change:** patch (top-level frames bigger than the device's screen scroll in the player; Change to, set variable and set variable mode lay out what they change in the player, as the canvas does; presentation tabs, one per page of a file; a Present tab with device and scale controls (#537); core editor leftovers: delays on mouse triggers and manual overlay offsets; controller buttons on key/gamepad triggers, widgets that react in prototypes, `proto.evaluate` and the mode lookup rules pinned) · **Target:** Figma Design (desktop app 126.10.7)
+> **Last reviewed:** 2026-10-11 · **Last updated:** 2026-10-23 · **Change:** patch (top-level frames bigger than the device's screen scroll in the player; Change to, set variable and set variable mode lay out what they change in the player, as the canvas does; presentation tabs, one per page of a file; overlay positions relative to the layer that opens them; a Present tab with device and scale controls (#537); core editor leftovers: delays on mouse triggers and manual overlay offsets; controller buttons on key/gamepad triggers, widgets that react in prototypes, `proto.evaluate` and the mode lookup rules pinned) · **Target:** Figma Design (desktop app 126.10.7)
 
 **Breadth ~92%, ready ~74% (estimated).** Every Figma trigger except media, every action except
 media control, every transition and easing exist; key/gamepad triggers take controller buttons,
@@ -51,6 +51,7 @@ case pins the current behaviour).
 | Open overlay: positions, background dimming, close on a click outside (on by default, can be turned off) | pass | `a_click_outside_an_overlay_closes_it_unless_turned_off`, `overlay_positions` |
 | Overlays stack; swap overlay replaces the top one; close overlay closes it | pass | `overlays_stack_swap_close_and_go_with_navigation` |
 | Manual overlay position relative to the hotspot | **added** | `offset: [x, y]` on the action, from the top-left of the layer that opens it (X / Y fields in the interaction editor; without one, below that layer); `present_delay_tests` |
+| Overlay position presets relative to the layer that opens it, inside or outside (not in Figma: [forum request](https://forum.figma.com/suggest-a-feature-11/set-overlay-position-relative-to-element-not-to-page-35366)) | **added** | `anchor: triggerInside \| triggerOutside` on the open overlay action; Relative to (Whole screen / Trigger layer) and Inside / Outside in the interaction editor. Outside: top presets above the layer, bottom presets below it, edges lined up (a dropdown is Bottom left + Outside); Center centres it on the layer. No flipping at the screen edge. `.fig` export writes a manual offset; `proto_overlay_anchor_tests`, `present_overlay_anchor_tests`, MCP `overlay_anchor` |
 | Delay on mouse enter / leave / down / up | **added** | `delayMs` on the interaction, a Delay field in the editor; fires once after the delay while its screen or overlay still shows (a pointer that leaves early: silent, it still fires); `mouse_triggers_wait_out_their_delay` |
 | Open link | pass | always a new tab or browser window (opening in place would leave the prototype) |
 | Change to: another variant of the instance, in place, with the interaction's animation | pass | `interactive_components_change_in_place` |
@@ -106,6 +107,7 @@ case pins the current behaviour).
 | 2026-10-23 | patch | A top-level frame taller (or wider) than the device's screen scrolls with no overflow setting, as Figma's documentation says; before, "No scrolling" frames such as the landing page template's Phone frame only clipped. Content past a frame's own edges still scrolls only as its overflow allows. Checked in the app on macOS. Numbers unchanged |
 | 2026-10-22 | minor | Change to, set variable and set variable mode lay out what they change in the player as the canvas does: text sizes to what it shows and hugging frames follow (an instance with a longer label changed to the main's width; a bound text kept its old size). Two player tests. Breadth and ready unchanged. |
 | 2026-10-17 | minor | Presentation tabs: one per page of a file instead of a single "Present" tab, named "file - page" (renames follow); Play shows a page's tab as it was; tabs outlive their file and come back when a saved file opens again. Numbers unchanged. |
+| 2026-10-17 | minor | Overlay positions relative to the layer that opens them (M5, beyond Figma, from a long-standing forum request): `anchor: triggerInside \| triggerOutside` on the open overlay action measures the position preset on the trigger instead of the screen (outside: top presets above it, bottom presets below it, edges lined up; Center centres it on the trigger). Relative to and Inside / Outside controls in the interaction editor, the player, MCP and `.fig` export (as a manual offset). Numbers unchanged. |
 | 2026-10-17 | minor | Community batch #753: a Present tab (#537): playback in its own tab that keeps its screen and history, a current-frame thumbnail, previous / next, device presets and scale; the frame reflows to the device's screen on the prototype's copy; phone and tablet content drags inside a fixed device as its overflow allows ("No scrolling" frames clip; iPad mini, MacBook Air and Desktop keep their bodies); the unsaved-changes question shows above the presentation. Checked in the app on Windows. Percentages and hours unchanged |
 | 2026-10-13 | minor | Prototyping, delays on mouse triggers and manual overlay offsets (M5): mouse enter, leave, down and up wait `delayMs` before their actions run (once while waiting; dropped when the screen or overlay they were on goes away; a pointer that leaves early doesn't cancel, the documentation is silent), and a manual overlay sits at `offset: [x, y]` from the top-left of the layer that opens it (without one, right below it, as before). Delay and X/Y fields in the interaction editor, the player on its own clock, REST import (`delay`, `overlayRelativePosition`), `.fig` import and export (the export's field for mouse delays is unchecked against other software). Numbers unchanged. |
 | 2026-10-12 | minor | Controller buttons on key/gamepad triggers (Controller menu, player polling on Windows and in the browser, REST import instead of skipping, control channel injection), widgets reacting to clicks in presented prototypes on the prototype's own copy, `proto.evaluate`; the mode lookup and set-variable-mode rules written as cases (they already held). Breadth 90% → 92%, ready unchanged at 74% (controllers on Windows and the browser only; no real prototype QA yet), 3–6 h → 2–5 h |