Soundbox v0.4.0

Added

• Studio: canvas layout and pop-out windows. The studio can lay its
  panels out as free cards on a grid instead of three columns: drag a card's
  header to move it, drag its edges to resize it, and Panels → Tidy puts it
  back. Positions are remembered per builder. Any panel can also leave the
  studio for a window of its own, so you can put it on another monitor. Drag
  its header past the edge of the window, or press its pop-out button. A
  popped-out panel shares the studio's state, opens its menus in its own
  window and passes keyboard shortcuts through. Closing the window puts the
  panel back, and docking or closing the panel, or leaving the studio, closes
  the window. The desktop app opens these as native windows.
• Failure cards. A generation or download that fails now says what
  happened, why, what to do and what is kept, with up to two fix links, Retry
  where a retry can help, the raw text under Details and a Copy diagnostic
  button, in place of a bare red line or a toast. The server classifies the
  common causes (GPU out of memory, system memory, paging file, missing
  runtime, model not downloaded, corrupt model file, stalled or truncated
  download, Hugging Face gated or unreachable, disk full, timeout) in
  server/src/failure.ts; jobs carry the result as failure. A failed
  generation also stays on the Library page as a card instead of vanishing.
• Command palette. Ctrl/⌘+K now finds sounds, stories, voices and models
  as well as pages: a sound opens, a story opens in its builder, a model
  loads, downloads or unloads from the row. Settings rows appear once you
  type. On a page with a composer the first row is Generate, or Cancel while
  a job runs. ? opens a keyboard cheatsheet.
• Script Builder: paste a script. Paste a scene or a passage and
  Auto-cast reads the speaker cues and "said X" attributions, hands each
  character a voice (a voice of the same name if there is one, otherwise the
  next unused one) and adds the lines; or split prose into lines by
  sentence, paragraph or chapter with a longest-line limit. An empty script
  offers Add first line, Paste a script and Load sample.
• Library. Every row carries its recipe (model, length, seed, steps,
  CFG, and whether it was extended or covered) so two takes of one prompt
  can be told apart; the sound page has a "How it was made" list with Copy
  recipe. A sound's menu has Send to: add it to a story, open it in the
  studio, or make a voice from it in the Voice Lab. The tag, model,
  favourites and by-agents filters fold behind a Filters button whose
  summary shows each chosen value as a chip that clears itself.
• Models page. Packs: one Install for a sensible model each for sound
  effects, music and voice at Fast, Balanced, Quality or Max, with the size
  to download; the category tabs say how many of each are on this machine;
  a model whose download stopped shows as Incomplete with Repair, which
  fetches only what is missing; and a Self-test in a model's details renders
  one second through the normal path and reports the time and device without
  saving anything (POST /api/models/:id/selftest).
• README. Shorter and faster to scan: a Make / Arrange / Connect table,
  a hardware table, profiles, an "install with a prompt" block for coding
  agents, and the source, Docker and API sections folded. docs/INSTALL-AGENT.md
  is the runbook that prompt points at.

Changed

• Composer. The Generate button keeps one width and names the running
  job's stage ("Loading model", "Generating 42%"), Cancel keeps its place
  instead of pushing the pills about, a progress strip runs along the card's
  bottom edge, and whatever stops a run is said in one sentence with the link
  that fixes it rather than a greyed-out button.
• Sidebar. Each area's icon carries its own hue, the sidebar folds to an
  icon rail on studio, Music and Voice Lab pages (with a "keep expanded"
  preference in Settings → Interface and on the rail itself), and the device
  row in the footer opens a panel with the GPU, VRAM in use, the loaded model
  and an Unload button that frees the memory without a trip to Models.

Installers are not yet signed. Windows shows a SmartScreen prompt (More info → Run anyway); macOS asks you to allow the app in System Settings → Privacy & Security. docs/DESKTOP.md has the details.