#486: move a panel into its own native window (multiple monitors)

Problem: floating panels lived inside the main window only, so on a
two-screen setup no panel could go onto the second monitor (#486).

Fix: panel menu > Move Panel to New Window (and the agent/control command
`window.panelWindow {panel, window?}`) undocks the panel if needed and shows
its floating group in a native egui viewport the user can drag to any screen;
Move Panel to Main Window or closing the window brings it back. The window's
place and size are kept in the workspace (sanitised against hostile values)
and restored on the next start. Browser and test builds, which embed
viewports, show it as an in-app window.

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

docs/gaps.md

@@ -76,7 +76,7 @@ are grouped by area; the issue tracker has the rest.
 | 17 | **Media Browser lists files import refuses** | `media_browser.rs` lists TGA, DPX, HDR, AVI, MXF; `media::is_importable` has none of them; #431 any image imports as a sequence; #324 MP3 goes silent | Confusing failures on common VFX formats (DPX, TGA) | 15–30 h | G6 · [file-format-parity.md](file-format-parity.md) |
 | 18 | **Relative paths and relinking** | Projects store absolute footage paths; no relink when a project moves | Moving or sharing a project breaks it | 6–12 h | G4 · [file-format-parity.md](file-format-parity.md) |
 | 19 | **Plug-in ecosystem** | No After Effects SDK hosting (#600, #327 OpenFX, #334, #376 plug-in manager); our WebAssembly API has no third-party plug-ins | Many pro projects depend on Trapcode, Element, Saber… | 40–80 h for API growth; SDK hosting needs an owner decision | G8 · [scripting-parity.md](scripting-parity.md) |
-| 20 | **Multi-monitor and video output** | #486 multi-screen, floating panels on other screens, Mercury Transmit to video hardware (we have a second preview window only) | Two-screen setups are standard for professionals | 10–20 h | G2 · [hardware-parity.md](hardware-parity.md) |
+| 20 | **Multi-monitor and video output** | #486: any panel can move into a native window of its own (panel menu ▸ Move Panel to New Window, `window.panelWindow`) and so onto another screen, restored with the workspace; still missing: dragging tabs between those windows, app shortcuts while one has the focus, named workspaces remembering them, Mercury Transmit to video hardware (we have a second preview window only) | Two-screen setups are standard for professionals | 10–20 h | G2 · [hardware-parity.md](hardware-parity.md) |
 | 21 | **Small 26.x features** | Proportional Scrubbing (26.2), copy frame to clipboard and paste SVG/AI as shapes (26.3), variable-font filter (26.3), percentage guides and effect colour labels (26.5), the rebuilt Effect Controls (26.5) | Users of the current version expect them | 15–25 h | — · [ui-parity.md](ui-parity.md) |
 | 22 | **Encoder efficiency** | HEVC / AV1 have no B-frames, multi-reference or SAO / CDEF; Opus no FEC / DTX; #372 uncompressed single-file output; #325 render over existing file | Larger files than After Effects + Media Encoder | 20–40 h | G6 · [file-format-parity.md](file-format-parity.md) |
 | 23 | **Essential Graphics interchange** | Templates are `.ectemplate`, not `.mogrt`; #338 Scale exposes X and Y; #611 FilmCraft rejects exported `.fcgt` | Premiere editors can't use our templates | 15–30 h | — · [file-format-parity.md](file-format-parity.md) |

docs/hardware-parity.md

@@ -22,7 +22,7 @@ monitors are missing, and two GPU start-up failures are open.
 | Video output devices | Mercury Transmit to AJA, Blackmagic, second display | second preview window only (Video Preview) | same | same | — | No SDI/HDMI device output |
 | HDR display | HDR monitoring on EDR / HDR displays | tone-mapped SDR view; no EDR output | no HDR output | no | no | Colour engine handles HDR maths (Rec. 2100 PQ/HLG output files) |
 | Pen tablets (pressure, tilt) | yes, for Paint and Roto | Brushes panel has pressure options, but no tablet pressure is read | same | same | same | Paint strokes store pressure per vertex; input never fills it |
-| Multiple monitors | panels and windows across screens | floating panels within one window only | same | same (#486) | — | gap 20 |
+| Multiple monitors | panels and windows across screens | panels move into their own native windows on any screen (Move Panel to New Window; desktop builds) | same | same (#486) | — | gap 20 |
 | Touch / trackpad gestures | pinch zoom in viewers | egui pointer and scroll; no pinch-to-zoom audited | — | — | — | — |
 | Audio hardware | Core Audio / ASIO / WASAPI, device choice, latency | cpal output; preview sound late on Linux (#554) and after a start offset (#504) | cpal | cpal (ALSA) | Web Audio | No input or device latency settings |
 | Machine learning acceleration | Apple Neural Engine / GPU for Object Matte, Roto Brush 3 | CPU inference (pure Rust, rayon) | CPU | CPU | CPU | No GPU inference for MobileSAM or MediaPipe |