fix(trash): align restore visuals with trash state and flow

[JoeJoeflyn]

Description

Fixes several misleading or missing trash/restore visuals reported in #1118:

• Restore icon: Restore context-menu items and the restore confirmation dialog showed a folder glyph identical to "Move to…". Both now use a bundled Lucide undo-2 icon.
• Trash fill level: The sidebar Trash icon was static. It now reflects the probed item count — outline (empty/unknown), low fill (1–4), half fill with a crest (5–14), solid bin with mound (15+). Count is enumerated capped at 32 items.
• Lid animation: The sidebar trash lid flips open during delete and restore flights and closes when they finish, with an open variant per fill level.
• Crosshair removal: Flying icons carried a ring border, shadow disc, and count badge that read as a crosshair/target. Flyers are now bare icons.
• Release animation: Restoring while viewing Trash animated icons out of the sidebar button toward disappearing rows — backwards. Restored items now lift off their rows and launch upward (coil, banked launch, shockwave/beam/spark burst) since the destination folder is not visible. The trash-to-row flight still plays when restored rows materialize in a normal folder, including the Ctrl+Z path which now animates via a post-restore retry.
• Ordering: The restore animation played before the confirmation modal. It now runs only after the modal is accepted; cancelling animates nothing.

Visual evidence

screenrecording-2026-09-18_20-20-10.mp4

Pending owner upload — gh cannot attach images. Local captures:

• /tmp/strata-trash-fill-levels.png — sidebar icon progression: empty / low (1–4) / half (5–14) / full (15+)

How to test

1. Open Trash, right-click an item → Restore → confirm in the modal — the icon lifts off its row and launches upward with a burst; the row then dissolves.
2. Select several Trash items and restore — the launch fans out per item.
3. Delete files from a folder — icons arc into the sidebar Trash button while the lid opens; the sidebar icon advances through low/half/full as the count grows.
4. Empty Trash or restore everything — the icon returns to the outline.
5. From a normal folder, press Ctrl+Z after deleting — once restored rows appear, icons fly from the Trash button onto them.

Expected result: restore uses the undo glyph, the sidebar icon tracks trash contents, flyers show no ring/disc/badge, restore-in-Trash animates items leaving upward after confirmation, and reduced-motion settings skip all flight animation.

Related issue

Closes #1118

[wmfeht]

request-changes on 82586f2c47343510d44252b51d57e8fb123bba3e.

Production change matches #1118 (restore uses undo-2, fill-level sidebar icon, bare flyers, restore-in-Trash launches upward, animation only after confirm, Ctrl+Z peek-then-fly). Drop these three tests — they are tautological / trivial getters. Do not add replacements.

1. launch_curve_explosive_burst (src/ui/browser/fly_to_trash/tests.rs) — asserts launch_curve(0)=0, (1)=1, (0.5)=0.875. That is 1-(1-p)³, which is also ease_out_cubic. Cannot fail unless f64 arithmetic is broken.

2. entries_named_returns_loaded_entries_matching_display_names (src/app/browser/tests/undo.rs) — fixture navigate + filter by "child" / "missing". Trivial getter around the columns.entries display-name filter.

3. the_trash_row_icon_fill_follows_the_probed_item_count (src/ui/window/tests/trash.rs) — six assert_eq! of trash_icon(…) against the match-arm constants. Restates the implementation literals.

Keep restore_flight_releases_only_when_every_entry_lives_in_trash, release_end_rises_above_the_row_and_fans_out, and pending_trash_undo_reports_original_locations_until_claimed.