fix: render theme-aware software cursors and mode banners

docs/architecture.md

@@ -65,7 +65,7 @@ Frontends inspect `file_picker()` for query, presentation, view, explorer-local
 Frontends inspect `diagnostics()` and `diagnostic_at_cursor()` for validated active-buffer annotations. Diagnostics are owned by core LSP or a plugin and buffer revision; text changes clear them. Native server retirement removes only that server's contribution, preserving sibling diagnostics. The TUI underlines annotated text, colors affected gutter numbers by severity, and displays the primary caret's diagnostic message without replacing search/selection backgrounds.
 Frontends borrow `semantic_tokens()` for sorted, single-line grapheme spans from the active buffer. Immutable `Arc` slices are shared by native LSP and buffer storage; painting does not copy tokens. Text replacements retain tokens outside the changed range and shift following positions using whole graphemes, including newline changes. Tokens overlapping the changed range are dropped; disjoint edits conservatively invalidate the range between their first and last changes. This applies to typing, undo/redo, completion, plugin replacements, and disk reloads. Path changes discard overlays. Native updates validate the whole applicable annotation batch before mutation. The TUI merges semantic styling into its existing glyph pass above syntax foregrounds but below diagnostic/search/selection/caret styling.
 Frontends inspect `hover()` for optional read-only content and logical-line/grapheme scroll offsets. Popup request eligibility, dismissal, and scrolling stay editor/session-owned; the TUI clips the panel inside the full editor area without changing the primary cursor or viewport. Its hover-local syntax cache treats content as Markdown, including named fenced-code injections, and rebuilds only when content changes. The popup shares the document syntax palette and preserves raw Markdown text and logical scroll coordinates.
-Frontends borrow `completion()` for the read-only item list and selected index: zero is Original text, and other indices select `items[selected - 1]`. The editor owns the immutable original document/carets, atomic candidate transactions, cycling/dismissal, pending Insert undo, and final-only repeat recording. It changes only the primary completion target and translates secondary carets through all edits. The TUI places a windowed list near the current caret, bounded by the full editor rather than its pane, sanitizes/clips labels and detail by grapheme, and preserves hardware cursor ownership; wheel input over the list is consumed without dispatching edits.
+Frontends borrow `completion()` for the read-only item list and selected index: zero is Original text, and other indices select `items[selected - 1]`. The editor owns the immutable original document/carets, atomic candidate transactions, cycling/dismissal, pending Insert undo, and final-only repeat recording. It changes only the primary completion target and translates secondary carets through all edits. The TUI places a windowed list near the current caret, bounded by the full editor rather than its pane, sanitizes/clips labels and detail by grapheme, and preserves logical cursor ownership; wheel input over the list is consumed without dispatching edits.
 Frontends borrow `snippet_selections()` for the active argument's end-exclusive grapheme ranges, including mirrors and empty tabstops. The editor caches those ranges after previews, argument edits, and navigation; rendering adds no snippet allocation. Template edits stay primary-only, translate other carets, and fold resolved replacement text and caret placement into the pending completion repeat step. Per-occurrence ancestry distinguishes nested arguments from adjacent empty stops, allowing enclosing replacements to retire only overwritten descendants.
 
 ## Terminal lifecycle and layout
@@ -74,13 +74,13 @@ The terminal guard owns raw mode, alternate-screen state, bracketed paste, mouse
 
 `tui::TerminalSession::run(inherited_screen, body)` scopes this ownership; `tui::run(&mut session, inherited_screen)` renders inside that active guard. On Unix, a fresh alternate screen pushes disambiguated keyboard flags so Ctrl+i stays distinct from Tab; final cleanup pops them. `TerminalSession::prepare_restart()` resets process-local input state without leaving the alternate screen or popping its keyboard flags. The replacement process inherits that stack entry rather than pushing another, and the guard stays armed if relaunch fails.
 
-Redraws stage Ratatui's buffer diff, cursor placement, and DEC synchronized-update commands (mode 2026) in a reusable byte buffer, then write and flush the complete frame to the terminal. Frame computation never suspends terminal presentation; synchronization covers transmitted painting rather than layout/highlighting work. The hardware cursor is hidden before painting even when synchronization is unsupported. Terminal cleanup releases synchronization before leaving the alternate screen or invoking caller panic diagnostics. Backend-writer access is enabled solely for this staging seam.
+Redraws stage Ratatui's buffer diff, logical cursor placement, and DEC synchronized-update commands (mode 2026) in a reusable byte buffer, then write and flush the complete frame to the terminal. Frame computation never suspends terminal presentation; synchronization covers transmitted painting rather than layout/highlighting work. `WheelPanels::cursor` records the final focused cursor position; the software cursor is painted after overlays, using the same named ANSI mode palette as the bars. `SoftwareCursorBackend` delegates drawing and cursor coordinates but suppresses hardware-cursor visibility, retaining input-method placement without a second cursor or OSC 12 dependency. The hardware cursor stays hidden even when synchronization is unsupported. Terminal cleanup releases synchronization before leaving the alternate screen, then restores cursor visibility before returning or invoking caller panic diagnostics. Backend-writer access is enabled solely for this staging seam.
 
 `terminal_colors` intercepts crossterm's key-shaped OSC 11/4 replies before editor dispatch, assembles a bounded RGB background/red/green triple, and preserves unrelated events and opaque bracketed paste. Queries never block input and start after painting, so syntax initialization does not spend their reply deadline. Startup, color-scheme notifications, and focus-regain queries replace cached diff tints atomically. While any rendered pane shows a diff, a one-second fallback probes for silent palette changes or missed notifications; ordinary editor views do not poll. Its injected-time deadline prevents overlapping periodic requests. An unanswered/partial query expires after 250 ms and removes stale tints rather than assuming a dark theme. Valid late replies are consumed without becoming editing commands. The frontend precomputes rounded RGB blends from the original background (18% row, 38% character), propagating them to active, parked, and newly created panes.
 
 `vendor/crossterm` retains Crossterm 0.29.0's upstream source and MIT license, with a small Unix decoder patch exposing `Event::ColorSchemeChanged` for `CSI ? 997 ; 1/2 n`. The report signals a palette refresh, not a choice of hard-coded light/dark colors. Valid fragmented reports and malformed color reports leave following keys intact. Cargo patches both direct and Ratatui dependency paths to this one copy; remove the patch/workspace member once upstream supports these notifications.
 
-The TUI allocates a flexible buffer viewport and optional one-row top/bottom bars, with no reserved prompt/message footer. Both bars derive visibility from configured content: empty content takes no row, and tabs-only content is hidden with a single tab in either position. Both render across ordinary, split, diff, and selector views. Ordered left/center/right groups use full-row centering, active-tab collision priority, internal padding, and independent styled edges. Floating Command/Search input owns the hardware cursor; non-focusable operation/diagnostic notifications anchor bottom-right inside the chrome-free workspace and hide obscured document carets. Higher-priority modal overlays suppress them without changing input state. Wheel hit regions clear each frame and consume reports over these popups. Zero-sized terminals render nothing; minimal-height input never reserves another row. Layout and terminal-cell text mapping remain frontend-owned.
+The TUI allocates a flexible buffer viewport and optional one-row top/bottom bars, with no reserved prompt/message footer. Both bars derive visibility from configured content: empty content takes no row, and tabs-only content is hidden with a single tab in either position. Both render across ordinary, split, diff, and selector views. Ordered left/center/right groups use full-row centering, active-tab collision priority, internal padding, and independent styled edges; accented content and edges share the focused mode's ANSI palette colors. Floating Command/Search input owns the software cursor; non-focusable operation/diagnostic notifications anchor bottom-right inside the chrome-free workspace and hide obscured document carets. Higher-priority modal overlays suppress them without changing input state. Wheel hit regions clear each frame and consume reports over these popups. Zero-sized terminals render nothing; minimal-height input never reserves another row. Layout and terminal-cell text mapping remain frontend-owned.
 
 Comparison views reserve no separate metadata header or native-buffer help footer. Revision labels render bottom-left in pane borders (combined on single-pane views), with per-side editability top-right and focus indicated by border styling. Dock and document geometry use the reclaimed workspace rows; conditional loading/error/file notices remain separate from the border metadata.