M12: stamps stick to the objects they land on, which are highlighted first (#1671)

* M12: stamps stick to the objects they land on

A stamp sticks to the topmost object under its centre (BoardItem::Stamp gains an optional on, left out when empty so older files open with stamps on nothing) and the board's normalize pass carries it when that object moves or turns, once when both move together. A stamp dragged onto another object sticks to that one, off everything to nothing; one whose object is deleted stays where it is. Gap 24.

* M12: the object a stamp will stick to is highlighted

While the stamp tool is over an object, or a stamp is dragged over one, the object it will stick to is outlined with the canvas's hover outline (Overlay::stamp_target, found by the same stamp_target as board.stamp and settle_stamps). A drag no longer drops what it moves into the auto layout of a sticky, shape with text or table: board objects take no drops; a stamp already inside its sticky moves with it once. Builds on #1671. Gap 24.

docs/boards-parity.md

@@ -43,7 +43,7 @@ all end with the same geometry.
 | Eraser | done | drag over marker and highlighter strokes to remove them, one undo step |
 | Pen colours and widths in the toolbar | partial | `tool.marker {color}`, `tool.highlighter {color}`; colour changes on a selected stroke from the contextual bar |
 | Stamps | done | thumbs up, heart, plus one, star, question, check: round badges drawn as vectors, the placer's name on hover |
-| Stamps sticking to the object they land on, the stamp wheel, emotes, stickers | missing | |
+| Stamps sticking to the object they land on, the stamp wheel, emotes, stickers | partial | a stamp sticks to the object it lands on (`on`) and moves with it; dragged onto another object it sticks to that one, dragged off it to nothing, and it stays where it is when its object is deleted. the object it will stick to is outlined while the stamp tool is over it or a stamp is dragged over it. No stamp wheel, emotes or stickers |
 | Text and sections | done | the existing Text tool and sections |
 | Live sessions: cursors, selections, cursor chat, spotlight | done | the existing sessions; board objects, connectors following moved objects, colours and stamps sync both ways (checked with two app instances) |
 | Timer | done | a pill at the top right of the board: presets (1, 3, 5, 10, 15 min) or any whole minutes, pause, resume, a minute more, stop; red at 0:00 until stopped; no sound. `board.timer {action, minutes?}`, `board.timerState`. Synced as its end time (or the time left while paused), so every client counts down on its own clock: nothing ticks over the network. Not an undo step |
@@ -64,6 +64,8 @@ all end with the same geometry.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-30 | minor | The object a stamp will stick to is outlined while the stamp tool is over it and while a stamp is dragged over it, as the incumbent highlights it; a drag no longer drops anything into a sticky, shape with text or table (board objects take no layers in). Numbers unchanged |
+| 2026-10-30 | minor | Stamps stick to the object they land on and move with it, as the incumbent's help describes; dragged onto another object they stick to that one, and they stay put, on nothing, when their object is deleted (the incumbent's help doesn't say). Numbers unchanged |
 | 2026-10-30 | minor | The contextual bar row: a selected connector's bar sets its start and end points, solid or dashed, its weight and any colour, beside the line type and the board colours (#1596). Numbers unchanged |
 | 2026-10-30 | minor | M12, gap 24: cells copied from a spreadsheet paste onto a board as a table. The clipboard carries them as text: a row per line, a tab between cells, and a cell holding a tab, a line break or a quote in quotes. `board_table::spreadsheet_cells` reads that into `board.table`'s `cells`. The table is centred in the view, or with Paste here its top-left goes at the point. Up to 50 × 20 cells are kept, with a note when there were more. Text without tabs, comma-separated text and any paste into a design file stay a text layer, as before. Tests: `board_table_paste_tests`, `table_paste_tests`. |
 | 2026-10-30 | minor | #1597: Shift+Cmd/Ctrl+Enter on a selected shape adds the next shape joined by a connector and starts typing in it; on a sticky it still adds a sticky beside it. Numbers unchanged. |

docs/gaps.md

@@ -563,7 +563,7 @@ No alpha blockers: the alpha gate in [`roadmap.md`](roadmap.md#alpha-gate) passe
   elbows that go around the objects they join.
 - **Missing:** timer music, board widgets, saving your own templates, table column resizing and
   cell colours, mind maps, washi tape, code blocks, audio and huddles, quick-create handles,
-  connector waypoints placed by hand, stamps sticking to the objects they land on, `.jam` files
+  connector waypoints placed by hand, the stamp wheel, emotes and stickers, `.jam` files
   ([`boards-parity.md`](boards-parity.md)).
 - **User impact:** boards cover a brainstorm, a retrospective, a flow sketch and a timed, voted
   workshop round.
@@ -573,6 +573,7 @@ No alpha blockers: the alpha gate in [`roadmap.md`](roadmap.md#alpha-gate) passe
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-30 | minor | Gap 24: stamps stick to the objects they land on and move with them; that item leaves the missing list (the stamp wheel, emotes and stickers stay). Estimate unchanged. Test: `board_tests::stamps_stick_to_what_they_land_on` |
 | 2026-10-30 | minor | Gap 10: library analytics count detached instances per component and file (reported by the file that detached them, kept by the server beside its usage, shown in Show usage and `library.usage`); insertions and counts over time remain. Estimate unchanged. Tests: `library_detach_tests` (server), `codec_tests::older_library_messages_keep_their_encoding`, `assets::library::tests::add_place_and_update_keep_overrides`, `detach_report_tests` |
 | 2026-10-30 | patch | Gap 15: `proto.linkNotice` (the Actions palette, the control channel, MCP) is saved with the preferences at once, as the notice's own "Don't show this again" is, instead of only when the app quits; that note leaves the missing list. Estimate unchanged. Test: `present_links_tests::skipping_the_notice_by_command_is_saved_at_once` |
 | 2026-10-30 | minor | Gap 6: plugin panels show pictures: an `image` control (`data` base64, at most 256 KB and 4,096 px a side; panel specs up to 1 MB) drawn at its size up to a field's width, named by its label, which shows instead when the picture can't be decoded. "Images" leaves the missing list; estimate unchanged. Tests: `v2_tests::panels_are_validated_and_keep_entered_values`, `plugin_panel_tests::panel_images_show_named_or_fall_back_to_their_label` |

docs/roadmap.md

@@ -75,6 +75,8 @@ blockers.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-30 | minor | M12, gap 24: the object a stamp will stick to is outlined under the stamp tool and while a stamp is dragged; board objects take no drops. Tests: `board_connect_tests`, `board_tests` |
+| 2026-10-30 | minor | M12, gap 24: stamps stick to the objects they land on and move with them (re-attach when dragged, let go when the object is deleted). Test: `board_tests` |
 | 2026-10-30 | minor | M9, part of #742: a team list on `figcraft-server`. With `team_files = "edit"` (or `comment`, `view`) everyone who reaches the server sees the files shared from it now (a link of theirs has a join code: Share ▸ Start sharing) and joins them by a team list link, `figcraft://join?server=…&file=…&team=1`, which carries no secret: the server hands out the file's team link while it stays shared (`ResolveTeam`, answered like a join code), and Stop sharing revokes it with the others, disconnecting whoever joined with it. Turning the list off or changing its access refuses the old team links at once. `collab.files {refresh}` asks the server in Preferences for its list (`Admin::Team`; not the public server FigCraft ships with), and Home ▸ Online shows it below your own files: a row joins its file, its menu copies the link for the app or, with the server's `web_url`, for the browser build (`<web_url>#join=…`). A browser build served beside its server names it with `<meta name="figcraft-server">`, the page's default for sharing, codes and the team list. No accounts: the list is for a server only your team reaches. Tests: `team_tests` (the server and apps over loopback), `code_tests` (links and the browser's driver), `online_tests` (the Online section), `query_tests` (the page's server). Percentages and hours unchanged |
 | 2026-10-30 | minor | M3, gap 10: library analytics count detached instances per component and file (reported to the server beside usage; Show usage and `library.usage`). Tests: `library_detach_tests`, `codec_tests` |
 | 2026-10-30 | minor | M12, #1596: the bar over a selected connector on a board had the line type and one arrow button. It now has, beside the board colours and the line type, a colour wheel opening the colour picker for any colour (when only connectors are selected), menus for the start and end points (every line end the Design panel offers, each shown), and a line style menu (solid or dashed, weights 1, 2, 4 and 6), each control naming itself on hover. The arrow toggle gave way to the end point menu. UI only: `board.setStyle` caps and the stroke's dashes and weight, one undo step each. Tests: `board_line_tests.rs` (headless). |