miniSCP/docs/architecture.md

# miniSCP architecture

Dense reference for development and debugging. Companion files:
[build-and-release.md](build-and-release.md), [platform-notes.md](platform-notes.md),
[gotchas.md](gotchas.md).

## Process model

- **Bun main process** (`src/bun/`): the native launcher runs electrobun's
  `main.js` on the Bun the 2.x devkit pins (1.4.0, shipped in the bundle —
  `build.mainProcess: "bun"`), which starts our bundle in a Worker. Imports the
  SDK as `electrobun/main` (projected into `.hutch/devkit/`). Owns every
  privileged capability: filesystem, SSH, window management, native
  menus/dialogs/tray, the connection/settings stores.
- **Webviews** (`ui/` Angular): one per window, system WebKit on macOS /
  WebView2 on Windows / WebKitGTK on Linux. Zero privileged access — everything
  goes through RPC.
- **RPC transport**: one WebSocket server in the bun process, multiplexed by
  `webviewId` (each webview auto-connects using natively injected globals;
  packets AES-GCM-encrypted per webview). 2.x Electroview queues sends while
  its `hostSocket` connects and falls back to a native bridge when the socket
  is unavailable. Requests are typed by the `AppRPC` schema in
  `src/shared/rpc.ts`.

### The one-schema rule

`AppRPC` is a single superset schema shared by all window kinds. This works
because electrobun allows **partial handler sets** (a side only implements
what it serves) and **silently drops messages nobody listens to**. Every
response crosses the bridge as `Result<T>` (`{ok:true,…}|{ok:false,error}`) —
exceptions never cross; `wrap()` in `src/bun/rpc-handlers.ts` enforces it.

### Per-window RPC instances (critical)

Each `BrowserWindow` MUST receive its own `defineRPC(...)` instance: binding a
BrowserView calls `rpc.setTransport(...)`, so a shared instance would have its
transport stolen by the most recent window. `createAppRPC` (main),
`createEditorRPC` (per editor window, hooks close over that window's record),
`createManagerRPC` (the single manager window), `createSettingsRPC` (the single
Settings window). `rpc.send.*` on an instance targets exactly its own webview.

### The `events` late-binding pattern

`createAppRPC` needs to trigger things that need `rpc.send` (which doesn't
exist until after construction). `AppDeps.events` is a mutable object of
no-op functions, reassigned in `src/bun/index.ts` after everything exists:
`sessionClosed`, `connectionsChanged`, `openEditor`, `settingsChanged`,
`openConnectionManager`, `openSettings`, `showAbout`, `applyUpdate` (the
update restart lives in index.ts beside the before-quit guard it must get past —
see build-and-release.md "Auto-updater").

## Window kinds

`src/bun/windows.ts` — `buildPreload(mode, settings, ctx?)` injects
`__APP_PLATFORM`, `__APP_MODE` (`main|editor|manager|settings`), `__APP_CTX`
before any page script, plus the persisted theme attributes and interface
scale so the first paint is already right. `ui/src/main.ts` picks the root
component from `APP_MODE`; all four roots use selector `app-root` (index.html
hosts only that tag). `chromeOptions()` is the ONLY place the native frame is
decided, spread by the main window and `openSecondaryWindow`: macOS `hiddenInset` +
`trafficLightOffset {x:12,y:4}` (2.x semantics — see gotchas; the UI renders an
`h-10 pl-24` drag-region header via `IS_MAC_CHROME`); other platforms keep the
native titlebar and a compact `h-9` non-drag header.

`WindowRegistry<Rec>` (same file): keyed window map with dedupe/activate,
cascade placement off an anchor frame, focus tracking. electrobun's emitter
has **no `off()`** — `track()` closures capture only `(this, key)` so closed
records can be garbage collected. A future "window follows window" grouping
belongs here (`anchor.on('move')` + `setPosition`).

### Editor windows (`src/bun/editor-windows.ts` + `ui/src/app/skins/shadlike/editor-window/`)

One window per file, key `sessionId+path` (sessionId, not fsKey: saves route
through a concrete session, and `local` is one shared session anyway).
Re-opening focuses the existing window. The webview fetches its own content
(`readFile`) — `openEditor` just creates the window with ctx in the preload.

**Close safety** (designed when electrobun window `close` was NOT cancellable —
1.18.1 had no `allow` response like `before-quit`; 2.x adds a cancellable
`will-close` for the titlebar close, not used yet — see gotchas):
1. ⌘W (the page's own `close-window` key; a ⌘W it doesn't claim falls through
   to the app menu, which bun routes back as `editorCloseRequest`) / Close
   button → styled in-window Save/Don't Save/Cancel, which takes focus (Save;
   ⌘S = Save, Esc = Cancel, Tab cycles) so keys can't edit the text behind it;
   the confirm path calls `editorClose` which sets `suppressPrompt` before
   `win.close()`.
2. Traffic-light close → the window is already gone, but the editor mirrored
   its draft to bun (`editorState`, 400 ms debounce + flush on blur/dirty-flip)
   → native Save/Discard box from the held draft. A failed save (dead session)
   parks the draft via `EditManager.rescueDraft` into the edits-leftovers dir,
   offered back at next boot. Known limit: the last ≤400 ms of keystrokes can
   be lost on an instant type-then-close.
3. ⌘Q → the app-level `before-quit` guard (cancellable) counts dirty editors
   plus running transfers.

`editorSave` is a dedicated request (not generic `writeFile`) so one handler
atomically writes + cleans the bun record + retitles + pushes `pathRefresh`
to the main window (panels showing that directory refresh). Editor upgrades:
scroll-synced line gutter (hidden when wrap is on — wrapped line numbers would
need per-edit height measurement), Alt/⌥Z wrap toggle, custom find bar
(matches computed in TS, `setSelectionRange` + scrollTop math — deliberately
not `findInPage`, which is a shim on WebView2). Find next / previous (⌘G /
⇧⌘G, F3 / ⇧F3) step from the caret with the bar open or closed — the query
survives closing it. Focus after a state change goes through
`afterNextRender({ injector })`: under zoneless CD a microtask runs BEFORE the
render that creates the `@if` element.

### Connection-manager window (`src/bun/manager-window.ts`)

Single instance, centered over main, **modal to main only** (editors stay
usable). No native modality exists (re-checked on 2.0.2: no parent/owner/sheet
option or input lock in any SDK or the core's exports; `styleMask.DocModalWindow`
is only the cosmetic NSWindow bit), so three layers approximate it: bun
bounces main's `focus` event back to the manager; the main webview renders a
click-swallowing overlay (`managerState` message); main drops its keyboard
shortcuts and bun drops main-targeted menu actions while open. Connect /
open-stack execute in the MAIN window via the `connect:<id>` /
`open-stack:<id>` menuAction channel (the manager closes right after — a
failed connect surfaces in main). Store edits push `connectionsChanged` so
main's `ConnectionsService` reloads; a reload-retry in `App.findConnection`
covers the save→connect race. `setAlwaysOnTop` is deliberately NOT used (it
would float over editor windows).

Keyboard (the `manager` keymap scope): ⌘N new connection (focus lands in
Name), ⇧⌘N new stack, ⌘S save, ⌘↩ connect — or, on a focused stack row, open
it in tabs — ⌘⌫ / Del delete the focused row (with a confirm), F2 rename the
focused stack, ⌘O import, ⌘W close. The list's rows are real buttons
(`data-row`; `data-stack` / `data-conn` say what they are): ↑ ↓ Home End move
FOCUS only — loading a connection would replace a half-edited form without
asking — Enter opens the focused connection in the form, ← / → collapse and
expand a stack (← on a connection climbs to its stack), and a stack's
hover-only actions also show while the keyboard is in its row. Enter in a form
field = Connect; Esc leaves a field first, then closes the window. Focus
returns where it was after a dialog (`focusin` memory + the FocusService
tick) and falls back to the edited connection's row whenever it drops to
`<body>`.

### Settings window (`src/bun/settings-window.ts` + `ui/src/app/skins/shadlike/settings-window/`)

Single instance, centered over main, **not modal**: every control is a plain
`SettingsService` setter, so each edit is an ordinary save that bun
rebroadcasts — the other windows follow live while it stays open. Opened by
the tab-bar gear and the open-settings key (⌘, / Ctrl+,, `openSettings` from
main) and, on macOS, the app menu's "Settings…". Its RPC serves only
`getSettings`/`saveSettings`/`pickEditorApp`/`showAbout`/`settingsClose`. Its
page claims its own close-window key (`settingsClose`); a ⌘W it doesn't claim
falls through to the app menu's Close Tab, and bun checks the Settings
window's focus FIRST and closes it (see gotchas). Sidebar sections (↑ / ↓ move
between them, focus starts on the current one, Tab is walked by `cycleFocus`):
Appearance, Transfers, Editor, File list (visible columns — the column-header
right-click menu toggles the same setting — and "Enter / double-click on a
file": nothing | open local files in their default app), Keyboard, About
(opens the native About box). The native title is `options.title`, retitled on
a locale switch.

**Keyboard** is the remap editor over the shared keymap: rows by group with a
search field (label or key text), a chip per combo (× removes), **+** records
(the next non-modifier keydown, taken before every other key in the window so
⌘W records instead of closing; Esc cancels; a click elsewhere or a blur ends
it), ↺ resets a row, Reset all (inline confirm). Reserved combos are refused
without `preventDefault` (⌘Q still quits); editor-scope combos must be chords
or F-keys (the editor's text area always has focus); a combo owned by an
overlapping-scope command offers **Replace** (moves it). Rows flag conflicts
and plain character keys on file-list rows (they no longer start a filter).
Fixed keys are listed read-only below. Every edit is `ShortcutsService.rebind`
→ `settings.keybindings` (only rows that differ from the defaults) → the
ordinary save + broadcast, so menus, tooltips and the macOS menu bar follow
live.

## Bun modules

- `fs/provider.ts` — `FileSystemProvider` interface: uniform local/SFTP ops +
  path helpers + streams + **`fsKey`** (see self-copy below).
- `fs/local.ts` — node:fs, `lstat`-based, `fsKey="local"`. Owner/group via
  cached `id -nu` / `dscacheutil|getent` spawns (win32 → undefined).
  `listLocalDrives()` for the Windows drive picker (`fsutil`).
- `fs/sftp.ts` — ssh2 under Bun (pure JS; native accelerators are build
  `external`s). POSIX paths always. `fsKey = resolvedIP:port` via `dns.lookup`
  at connect. Owner/group parsed from the ls-style readdir `longname`.
  Keepalive 15 s; `closedByUs` flag so `dispose()` doesn't fire the onClose
  callback. mtime seconds→ms; mode masked `& 0o7777`.
- `fs/registry.ts` — sessionId → provider map; `"local"` is built-in;
  `add()` mints `sftp-<n>`; `drop()` (session died) vs `remove()` (clean).
- `fs/watcher.ts` — `LocalDirWatcher`: `fs.watch` handles keyed by dir,
  debounced ~150 ms (watch fires bursts). Drives local auto-refresh: the main
  webview sends `setWatchedDirs` (the active tab's local panel cwds); a change
  fires `onChange` → `rpc.send.pathRefresh({sessionId:"local", dir})`.
  `onChange` is late-bound in index.ts (the `events` pattern). SFTP has no
  watch, so remote panels are polled UI-side instead (see panels.service).
- `transfers/engine.ts` — FIFO job queue. `Semaphore` with live resize
  (`wake()` reserves slots synchronously — an async waiter increment was a
  race). Per-job worker pool (`MAX_WORKERS_PER_JOB=8`) draws from the shared
  slot budget, so in-folder parallelism and cross-job fairness share one knob
  (`setConcurrency` from settings; `single` mode = 1). `activeStreams` set
  enables hard cancel. `emit` throttled 100 ms. `failSession` fails that
  session's jobs. Probe files: `.{appname}-probe-*`.
- `transfers/walk.ts` — recursive tree walk (segment arrays, skips symlinks)
  + `removeRecursive`.
- **Self-copy protection** (data-loss class): copying a file onto itself
  truncates it (`createWriteStream` O_TRUNCs before the read). Guards compare
  **fsKey, never sessionId** — two sessions to one server are distinct
  sessions on one filesystem. When fsKeys differ but paths collide,
  `probeSameFilesystem` writes a token via dst and reads it via src to unmask
  hidden aliases (SFTP has no dev/inode). Fails open (permissions produce
  their own error). Residual risk (documented in README): same filesystem
  mounted at different paths.
- `edits.ts` — `readFileText`/`writeFileText` (2 MB cap) for the built-in
  editor; `EditManager` for the external-editor flow: temp-download under
  `appDataDir()/edits/<id>/` + `meta.json`, directory watch (survives atomic
  renames), 400 ms debounce → engine upload. Watchers die with their session;
  leftover dirs are offered for cleanup at boot. `launchEditor` is the
  platform seam (`open` / `cmd /c start` / `xdg-open`).
- `store/paths.ts` — per-OS `appDataDir()` + `migrateLegacyDataDir()` (renames
  a `BRANDING.legacyNames` dir into place on boot; list currently empty).
- `store/connections.ts` — plaintext-passwords JSON (deliberate v1 choice),
  atomic tmp+rename, 0600 + win32 `icacls` ACL. `store/settings.ts` — defaults
  spread-merge on load, so NEW SETTINGS KEYS need no backend change.
- `menu.ts` — macOS-only app menu, rebuilt on every connections change (the
  Connect submenu mirrors the store), language switch and keyboard remap.
  **Accelerators come from the shared keymap** (`effectiveKeymap` +
  `toAccelerator`, the first combo the native parser can express faithfully:
  ⌘/⌃ chords only — a bare key means ⌘+key to it — no ⌫ / ⌦ / Shift+punctuation);
  ⌘Q stays fixed. The keybindings are read through a getter AFTER the
  connections load, so a remap saved meanwhile isn't lost. The page claims the
  keys it handles first, so the menu only runs what falls through; a
  `close-tab` that still arrives while a Settings or editor window is focused
  closes THAT window, and other main-targeted actions bring the main window
  forward first. Labels go through
  backend `i18n.t` and the menu is rebuilt on a locale change too.
- `i18n.ts` — backend translator (native menus + thrown error messages, which
  no Angular service can reach). `setLocale(setting)` caches the resolved
  locale (from `settings.locale`, `system` via `Intl…resolvedOptions().locale`);
  `t(key, params)` shares the same `src/shared/i18n` dictionaries as the UI.
  Wired in index.ts on boot and on `settingsChanged` (relocalizes + rebuilds
  the app menu). The context menu no longer needs this — it is Angular and reads
  `I18nService` directly.
- `tray.ts` — static icon, click = activate main. macOS template image;
  Windows colored icon. No `setImage` calls ever (they lose the template
  treatment) and no menu (clicks arrive directly).
- `index.ts` — composition root: wiring order matters (events assigned after
  rpc; manager/editors constructed after win; quit guard; focus tracking for
  notification suppression across all windows).

## UI layout

```
ui/src/app/
  core/            app.config.ts, icons.ts, platform.ts, format.ts, file-icons.ts,
                   metrics.ts and every *.service.ts — the non-visual layer
  skins/shadlike/  the component tree: four window roots (SHAD_ROOTS barrel,
                   picked by main.ts), dialogs, context menu
```

Components reach `core/` through the **`@core/*`** tsconfig alias (alongside
`@shared/*` → `src/shared`), which is deliberate: components sit at varying
depths and an alias keeps their imports identical wherever a file moves. Do not
replace it with relative paths.

**Where a new rule goes**: behaviour → `core/`; markup and appearance → the
component; tokens → `ui/src/styles.css`.

## UI services (`ui/src/app/core/`)

- `rpc.service.ts` — wraps `Electroview.defineRPC`. **Push messages fan out
  through plain callback registries, never signals**: a signal consumed from
  an effect that also writes signals re-triggers itself (this froze the whole
  app once), and signal coalescing drops progress snapshots. All requests are
  gated on the socket-open promise (`electroview.hostSocket`) — on 1.18.1 calls
  fired during boot were silently lost; 2.x Electroview queues them itself, so
  the gate is belt-and-braces now. `request` and `send` are ready-gated Proxies.
- `panels.service.ts` — `PanelState` (per panel): sessionId, fsKey, cwd,
  entries, sort, cursor, selection, type-to-filter. `sorted` computed:
  filter → dirs-first sort (name/size/mtime numeric, kind/rights/owner/group
  via display-string compare) → synthetic `'..'` row unshifted unless
  `isRootPath(cwd)`. `touched` marks user navigation (connect flows only
  auto-load `localDir` into an untouched local panel). `connectToken`
  supersedes stale connects. `Workspace` = tab = left/right pair + activeSide.
  Remote goes RIGHT on connect/open-stack (commander convention); per-panel
  dropdown connects target their own panel. **Auto-refresh** (always on):
  `refresh({silent})` re-lists without the loading/busy flags and touches no
  DOM (scroll/cursor/selection/filter preserved), snapshotting sessionId+cwd
  to discard results if the user navigated mid-flight. Only the active tab is
  live: its local panels are fs.watched (backend `setWatchedDirs` effect +
  `pathRefresh` push → silent refresh), its remote panels polled every 3s
  (`REMOTE_POLL_MS`); switching tabs silently refreshes the newly-active pair.
  A future on/off setting is stubbed in commented breadcrumbs (types.ts,
  settings.service, tab-bar).
- `transfers.service.ts` — jobMap from `transferUpdate` callbacks; EMA speed
  (`SPEED_SMOOTHING=0.7`); `copyToOtherPanel` guards same-fs+same-dir before
  enqueue and runs the collision flow (same-path auto-skip, type-mismatch
  skip, overwrite dialog with all/none batch modes).
- `settings.service.ts` — one signal per setting; **imperative apply pattern**
  (`applyTheme/DarkTone` set `data-*` attributes on `<html>`;
  `applyUiScale` sets its inline `font-size`); `applyAll` also serves the
  `settingsChanged` broadcast, so every window follows a save made in any
  other. Every window RPC serves `saveSettings` (editor and manager windows
  save too — the scale shortcuts — and the Settings window is nothing but
  saves); bun's `settingsSaved()` in index.ts runs the
  side effects once and rebroadcasts to every window **except the sender**, so
  there is no echo to fight a held Cmd+. `applyAll` never persists. Saves are
  whole-object, so **nothing persists until the first `getSettings` landed**
  (`loaded`): a ⌘+ pressed while a window opens would otherwise write the
  defaults over every remap. New setting = five touches here + types.ts
  (backend merges automatically; sanitize hand-editable shapes in
  `SettingsStore.load`).
- `focus.service.ts` — dependency-free `tick`/`bump()`; dialogs bump it, the
  main window's panels listen — but a panel only takes focus while NO dialog or
  menu is up (a run of overwrite questions reuses one dialog instance; focusing
  the list behind it handed Enter/Delete to the panel). Exists so dialogs don't
  inject PanelsService (whose constructor spawns a workspace — fatal in
  secondary windows).
- `shortcuts.service.ts` — the keyboard layer over `src/shared/keymap.ts`; see
  "Keyboard" below.
- `focus-cycle.ts` — `cycleFocus(root, event)`: Tab / ⇧Tab by hand (see
  "Keyboard").
- `connections.service.ts` — store mirror + ssh-config hosts; reloads on the
  `connectionsChanged` push.
- `i18n.service.ts` — runtime translator. `locale` signal + `t('ns.key', params)`
  (dotted lookup, `{param}` interpolation, `{one,other}` plural maps via
  `Intl.PluralRules`); missing keys fall back to English then the raw key.
  **Reactive by design**: `t()` reads the `locale` signal, so every template
  binding that calls it re-renders live on a language switch (call-stack
  tracking, see gotchas.md) — no pipe. Also exposes locale-aware `date()`/`size()`
  /`speed()` so the file list reformats on switch. `SettingsService.applyLocale`
  resolves the `locale` setting (`system` → `navigator.language`) into it, on
  boot and on the `settingsChanged` broadcast (so editor/manager windows follow).
- `file-actions.service.ts` — **one file-command dispatcher**,
  `run(id, { side, panel, entry })`, for every entry point: list keys (the
  cursor row), row-menu picks (the right-clicked row, captured in the menu's
  `onPick` closure), the macOS menu bar's File/View items and the panel
  toolbar. Ids are keymap `FileCommand`s (`open`, `open-default`, `send`,
  `edit`, `rename`, `new-folder`, `new-file`, `chmod`, `delete`, `trash`,
  `copy-path`, `reveal`, `refresh`, `sort-*`). Selection if any, else the
  target row; `..` stands for the folder. `open` enters folders and opens a
  LOCAL file in its default app only when `openFilesOnEnter` is set (Settings
  → File list); `open-default` (the menu's Open on a local file) always does.
  `trash` walks the selection one `moveToTrash` at a time. Main-window only
  (it injects TransfersService).
- `context-menu.service.ts` + `skins/shadlike/context-menu.ts` — the panel and tab right-click
  menus, in HTML. Electrobun's native `showContextMenu` is a no-op on Linux, so it was
  retired on ALL platforms rather than kept as a second code path (see
  platform-notes.md). The service builds the item list (row / empty-space menu,
  the header column picker, and the panel **source picker** — Local, drives,
  connections under per-stack `header` items, `~/.ssh/config` hosts — which
  replaced a bespoke popover so it gets the same keys and look) and holds the
  open request as a signal; the component renders it at a point
  (`MenuPoint`: a MouseEvent, or a row rect for a keyboard-opened menu) with
  edge-flip clamping, a scrolling clamped box, and close-on-blur/resize/scroll.
  Items carry `shortcut` (a keymap id: its first key is the soft hint at 60%
  of the row colour, and pressing it while the menu is open picks the item)
  and `icon` (drawn in the check column; only the everyday verbs get one —
  Send, Edit, Rename, Delete, New Folder, New/Close Tab, the toolbar's own
  glyphs). Keys: ↑↓ Home End move the one highlight (mouse hover shares it),
  Enter/Space pick, Esc closes, items are not Tab stops; every handled key
  stops propagation so the window handler never runs it twice. A keyboard-opened
  menu starts with its first item highlighted (`initialIndex`). A request's
  `onPick` takes the pick (row menu → `FileActionsService.run`, source picker →
  `FilePanel`); otherwise `col:*` / `tab:*` strings go through
  `RpcService.emitMenuAction` to the SAME `App.handleMenuAction` dispatcher the
  macOS app menubar uses. The three shell actions the webview cannot perform
  (reveal, open-with-default, copy path) go back to bun via the
  `shellItemAction` RPC, which is all that remains of the old native menu.
  `tabItems()` builds the workspace-tab menu (`tab:new`, and
  `tab:close|close-others|close-right|disconnect:<id>`), served by
  `PanelsService.closeOtherWorkspaces` / `closeWorkspacesToRight` /
  `disconnectWorkspace`. **The target id travels inside the action string**: the
  right-clicked tab is not necessarily the active one, so nothing on that path
  may fall back to `activeWorkspaceId`. Illegal entries are `disabled`, not
  omitted — a menu whose items move between right-clicks is worse than one with
  a dead row. The disabled styling (`pointer-events: none`) only stops the
  pointer; the keyboard path never consults it — so `pick()` and the arrow-key
  walker check the flag themselves.
- `file-icons.ts` — extension → category map driving glyphs, colors
  (fixed `--icon-*` tokens from Oxide's hue scales) and the Kind column.
- `icons.ts` — the one icon registry, passed to `provideIcons` in `app.config.ts`.
  A name is `<icon><px>`: the pixel grid its glyph is drawn for, which must match
  the size token where it renders (`server14` at `--icon-size-sm`, `server16` at
  `-md`, `server24` at `-xl`). The one exception is `tdesignLoading`, which spins.
  Every glyph is TDesign's shape redrawn on its pixel grid in `pixel-icons.ts`,
  as whole-pixel runs plus 1.25px slants (rules in gotchas). Only `closeCircle24`
  (TDesign's own 24px grid) and the spinner still come from
  `@ng-icons/tdesign-icons`. Templates can't type-check
  icon names, and an unregistered one renders nothing (a console warning only), so
  `icons.spec.ts` checks every `<ng-icon>` in the skins. TS code that picks an icon
  takes the `Icon14` / `Icon16` types.
- `platform.ts` — preload-global readers (`PLATFORM`, `APP_MODE`,
  `EDITOR_CONTEXT`, `IS_MAC`/`IS_MAC_CHROME`, `IS_WINDOWS`, `IS_LINUX`) +
  `blockNativeContextMenu` (kills WebKit's Reload/Inspect menu outside text
  fields — the app draws its own menu instead) + `blockReloadKeys` (swallows
  unclaimed F5 / Ctrl+R / Ctrl+F5 / Ctrl+Shift+R on Windows, where WebView2
  would reload the page and drop every session; each window root calls it
  last).
- `updater.service.ts` — auto-updater state for the tab-bar pill. Signals
  `state` (`idle→available→downloading→ready`|`error`), `version`, `progress`.
  Subscribes the `updateStatus` push (backend `Updater.checkForUpdate` on
  launch+6h, `onStatusChange` progress); `ready` is derived when the
  `downloadUpdate` request resolves ok (not a pushed phase). `download()` /
  `apply()` (relaunch) / `check()` (menu). Backend wiring lives in
  `src/bun/index.ts`; feed is `release.baseUrl` (`https://miniscp.com/dl`, the
  `/dl` host in `site/`). See build-and-release.md "Auto-updater".

## Keyboard

**One keymap** — `src/shared/keymap.ts`, shared so the webviews and bun (the
macOS menu bar) read the same table. `BINDINGS` lists every command: `id`,
`group` (Settings sections), `scopes`, and default combos per platform
(`mac` / `other`, best first: the first is the hint menus and tooltips show).
Combos are platform-neutral strings (`Mod+Shift+N`: Mod = ⌘ on macOS, Ctrl
elsewhere; `Ctrl` a literal ⌃ only macOS tells apart). Letters match the
layout's character (AZERTY's A is A) and fall back to the physical key under
Alt (⌥Z types Ω) and on non-Latin layouts; digits match physically (AZERTY
types "&" on 1); punctuation by character first (AZERTY's comma is on the M
key), physical second (⇧] makes "}"). **Matching is exact**: ⌃F is not ⌘F,
Ctrl+Tab is not Tab, and neither the Windows key nor AltGr is ever part of a
binding. `effectiveKeymap(overrides)` applies `AppSettings.keybindings`
(rows that differ from the defaults; `[]` unbinds) and drops anything
malformed. `conflicts()` / `ownerOf()` work over overlapping scopes; the
spec (`keymap.spec.ts`) proves the defaults conflict-free, round-trippable and
unshadowed on both platforms.

**Scopes.** `panel` = the focused file list (navigation, file commands,
sorting); `main` = anywhere in the main window (tabs, window commands); `editor`
/ `manager` / `settings` per window; `any` = every window (interface scale).
`panel` sits inside `main`, so they conflict-check together.

**`ShortcutsService`** resolves keydowns against the effective keymap
(reactive: a remap applies live in every window via the settings broadcast) and
formats hints — `label(id)` / `labels(id)` / `tip(text, id)` /
`tipFixed(text, 'Shift+Enter')`, with **localized key names** off macOS
(`keys.names.*`: German says Strg+Entf). `claim()` = resolve + `preventDefault`
(so the macOS menu never runs it twice) + auto-repeat only for movement-like
commands (holding ⌘W closes one tab). IME composition is never a shortcut.
From a text field only `firesInTextField()` combos count: ⌘/Ctrl and Alt chords
and F-keys, but not plain keys, not text-editing chords (⌘⌫, ⌥←, ⌘A) and not
Ctrl+Alt off macOS (AltGr).

**Dispatch** (one place per window): an open context menu owns its keys; an
open dialog owns Enter / Esc / Tab while the main window swallows window
commands and the panel commands the macOS menu bar carries (an unclaimed ⌘T
would otherwise reach the menu and open a tab behind the dialog); the focused
list (`FilePanel.onKeydown`) runs, in order, the fixed filter-editing keys
while a query is typed, the `panel` keymap (Shift + a movement key extends the
selection over the rows passed — a fixed rule that follows remaps), lets
`main` matches bubble, then type-to-filter, then Esc's fixed chain (clear the
filter → cancel a connect → clear the selection); `App` runs `main`. Every root
ends with `blockReloadKeys`. Keys that land on `<body>` (a click dropped focus)
are forwarded to the active list (`PanelsService.forwardListKey`), and `App`'s
`(mousedown)` keeps focus on the list after chrome-button clicks.

**Remaps** live in `AppSettings.keybindings` (sanitized on load), edited in
Settings → Keyboard (see the Settings window). `ShortcutsService.rebind`
stores only rows that differ from their defaults.

**macOS key equivalents are page-first.** WKWebView hands ⌘-keys to the page
before the app menu (WebKit `WebViewImpl::performKeyEquivalent`); only keys the
page doesn't `preventDefault` reach the menu bar. So the page owns every app
shortcut, and a window that doesn't claim a key lets it fall through to the
menu (⌘W in a window whose close-window was remapped away still hits Close Tab,
which bun routes to the focused Settings / editor window first).

**Focus without Keyboard navigation.** WKWebView's Tab skips buttons,
checkboxes and radios unless the user turned on System Settings → Keyboard →
Keyboard navigation, so `cycleFocus(root, event)` walks Tab / ⇧Tab by hand
(DOM order, wrap, a radio group is one stop): every dialog (it is also their
focus trap), the transfer list (⌘J opens it focused), the editor's save prompt.
Dialogs carry `role="dialog" aria-modal`, take initial focus (the chmod dialog
on its octal field, Enter applies) and stop Esc from propagating — a
window-level Esc (the connection manager closes on it) must not see it too. A
base-layer `:focus-visible` ring in `--ring` marks the focused control.

**Opening a row's menu from the keyboard**: ⇧F10 / the Menu key / ⌃↩ (macOS)
open the cursor row's menu under the row, first item highlighted; the
selection is kept, its commands act on it like the F-keys do.

## Theming

`ui/src/styles.css`: OKLCH tokens adapted from **Oxide's design system**
(docs.oxide.computer: a cool neutral scale at hue 260 with almost no chroma,
one green accent, opaque strokes; the comments carry Oxide's step names
n0…n1300 / green-800). Dark values are duplicated in `:root[data-theme='dark']`
AND a `prefers-color-scheme` media block (system mode) — every dark token
change goes in BOTH; retone neutrals along the one scale, or warm and cool
surfaces clash. **There is no accent setting**: `--primary` is Oxide green per
theme (green-800 dark, green-500 light), so selection (`bg-primary/15`), the
cursor row (`--cursor-tint`, a `color-mix` of `--primary`), focus rings
(green-600) and `--success` all read green. **Surface layers**, each its own
shade: `--chrome` (frame — tab/transfer/status bars, the editor/manager/settings
header+footer strips and sidebars), the file panel's header strip **stepping
toward the list** — session strip `--toolbar`, path bar `--toolbar-2`, column
headers `--toolbar-3` (`color-mix` steps declared once in `:root`, so every
theme follows) — then `--background` (file lists, editor text, forms;
`--row-alt` stripes odd file rows, skipped on the cursor/selected row so two
`bg-*` utilities never fight) and `--card` (popovers, dialogs, toasts). The
right-click menu is the exception: the darkest surface (`bg-chrome`) behind a
faint `border-border/60`, and its highlighted item takes Oxide's selected style —
`--primary-surface` fill (Oxide surface-accent: green-200 dark, green-1200
light) with `text-primary`; mouse and keyboard share that one highlight
(`activeIndex`). The
ACTIVE panel is marked by a 0.125rem `--primary` line along its top edge (an
inset box-shadow on the session strip, so switching panels never shifts
layout). Dark: frame 0.162 < list 0.195 < header 0.275 → 0.248 → 0.221 < card
0.29; light steps greys out from near-white content: frame 0.925 < header 0.95
→ 0.965 → 0.98 < list = card 0.995. **`--accent` is translucent** (n0 at 5%
light, white 7% dark): hover/selected states sit on every layer, and an opaque
hover vanishes on a surface of its own lightness. Strokes are opaque
(`--border` n300 dark / n900 light, `--input` one step stronger). The
"darker" tone is true-black AMOLED: chrome, background, toolbar (+ its steps)
and row-alt are all `#000` (the layers collapse on purpose); elevation
survives only via `--card`/`--muted`/`--accent` (opaque there). **Square
design**: no `rounded-*` utilities and no radius tokens; an `@layer base`
block restyles native controls to match — checkboxes/radios (`appearance:
none`, a drawn check / square dot), selects (a `currentColor` caret; use
`pl-*`, never `px-*`, on a select), hidden number spinners, and square
`::-webkit-scrollbar`s (which make macOS scrollbars always visible).
`@theme inline` maps tokens to Tailwind utilities (`bg-primary`,
`text-icon-folder`, `bg-toolbar-2`, `bg-cursor-tint`). File-type icon colors
come from Oxide's hue scales (800 steps dark, 600 light). **Icon sizes** follow
TDesign's rule (an icon is 2px larger than its text, in whole pixels) through
four rem tokens, and every `<ng-icon>` takes one: `--icon-size-sm` 14px (beside
11–12px text, small icon buttons), `-md` 16px (13–14px text: file rows, window
titles; the path-bar buttons), `-lg` 20px and `-xl` 24px (lone spinners and
status marks). The glyphs are drawn on the sm, md and xl grids (`icons.ts`).
**Interface scale** (`settings.uiScale`,
0.5–4 in 0.1 steps): one root font-size lever — `applyUiScale` sets
`html { font-size: 16px * scale }`, and since EVERY size in the app is rem
(panel tokens like `--row-h`, all Tailwind utilities, ng-icon sizes), the
whole UI scales, chrome included.
Driven by the Settings window's stepper, Ctrl/Cmd +/−/0, and preload-baked for a
flash-free first paint. It replaced the 3-tier `data-text` axis; the store
migrates old `textSize` values. TS that measures rem-sized CSS converts through
`@core/metrics` `remPx()` — never an assumed 16.