Move AOI's analyze and cancel card onto the core popup service

[CarsonDavis]

Category	Lines added	%
Tests	753	74.0%
Production code	265	26.0%

AOI's analyze card is now the core popup, and every way of closing it clears the selection.

Closes #299

The analyze card is the core popup

Previously the card was AOI's own tooltip, mounted through the overlay API with its own CSS. A plugin cannot ship DOM across a sandbox boundary, so the card became data. It is now the core card, same "Analyze area" then "Cancel" order, label on top, anchored above the selection centre. Demo mission: search a state.

What each way of closing does

Analyze is unchanged: it hands the selected feature to the statistics and chart plugins and leaves the highlight up. Previously only Cancel cleared the selection. Now Cancel, the X, Escape and a click on empty map all clear the selection and its highlight; a card that code replaced or retracted leaves it alone. A click on a feature dismisses nothing, so a new selection replaces the open card. Demo mission: all four, then a second state.

Drawing over a selection

Previously the card sat there through the whole drawing session. Now starting a drawing parks the selection and takes the card down, cancelling before a vertex brings the card back, and the first vertex drops it for good. AOI's own subscriptions now go through its handle, so they are released with it. Demo mission: open a card, draw, press Escape; repeat and click once.

Shape identity, lines and points

The panel follows the shape the engine started, not the button pressed, visible when switching shape mid-session. Centroid and bounds now handle linestrings and points. Demo mission: shape identity yes; lines and points only if the mission's draw shapes include them, not the default three.

Closing AOI mid-flight

Previously a selection made and instantly closed could leave an orphan card 1.5 s later. Now AOI's teardown disarms a card still waiting on the camera, core closes any card already open when the plugin is destroyed, and a selection superseded before its card opens never opens one. Demo mission: select, then close AOI. The tooltip component and its styles are gone, and the unused drawingCancelled event with them.

Decisions to review

• Drawing a new area suspends the previous selection and can restore it. drawstart retracts the card but keeps the selection, the first vertex drops it (plugin:aoi:drawingCleared now fires mid-session, not at completion), and drawcancel reopens the old card. Restoring re-anchors without re-framing, so a selection panned off screen gets its card at the view centre.
• The label goes as title, rendered as text, not an html body. Labels from boundary data and uploads cannot inject markup, but the body slot stays unused, so a future "size under the name" needs a contract change, not a payload one.
• Centroid and bounds were generalized from polygons to lines and points. A linestring selection now gets a card and can move the camera; a point yields a degenerate bbox the fit step refuses, so its card may land at the view centre. The alternative was guarding the popup path instead.
• plugin:aoi:drawingCancelled is gone from AOI's emitted contract. Nothing in the repo listens, so the blast radius is zero today; it matters more once plugins are third-party artifacts. The alternative was keeping it on a secondary press.

[CarsonDavis]

Superseded by #456 (AOI migration onto the core popup service).