Fix desktop launch, app icons and keyboard parameter editing

docs/book/src/guide/getting-started.md

@@ -19,6 +19,31 @@ cargo run --release -p solvecraft -- --sample   # opens with a sample part
 `solvecraft design.solvecraft` opens a saved design. Windows builds cross-compile from Linux with
 `cargo xwin build --release --target x86_64-pc-windows-msvc -p solvecraft`.
 
+### Linux Flatpak
+
+Install Flatpak using your distribution's package manager. For an installation that receives
+updates, add Flathub for the required Freedesktop runtime and the SolidCraft application feed
+to the same user installation:
+
+```sh
+flatpak remote-add --user --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo
+flatpak remote-add --user --if-not-exists solvecraft https://bherbruck.github.io/solidcraft/flatpak/solvecraft.flatpakrepo
+flatpak install --user solvecraft ai.storyteller.solvecraft
+flatpak run ai.storyteller.solvecraft
+```
+
+The application ID and remote name retain their compatibility names. To update an existing
+remote that still uses the former website address, run
+`flatpak remote-modify --user --url=https://bherbruck.github.io/solidcraft/flatpak/repo/ solvecraft`
+and then `flatpak update --user`.
+
+Alternatively, download the release's `.flatpak` file for your architecture and run
+`flatpak install --user ./solvecraft-VERSION-linux-ARCH.flatpak`. The bundle supplies the
+Flathub runtime repository address; installation still needs internet access to fetch any
+missing runtime. Launch with `flatpak run ai.storyteller.solvecraft`, rather than looking for
+a host `solvecraft` binary. Files chosen through Open/Save use the desktop file-chooser portal;
+command-line paths outside Documents may need a specific additional filesystem permission.
+
 ## Web
 
 The same app runs in the browser: [open SolidCraft on the web](../app/) (`?sample` opens the sample

docs/book/src/guide/parameters.md

@@ -9,6 +9,12 @@ In the SOLID toolbar's CONFIGURE panel, click **Parameters** to open the user an
 parameter editor. The separate **Configurations** button opens the configuration table;
 **Configure** remains in the dropdown for configuring columns.
 
+Press **Enter** in the new parameter's name, expression or comment field to add it.
+Valid entries return focus to the name field for the next parameter; invalid entries remain
+editable. In expression fields, **Up/Down** selects an autocomplete suggestion,
+**Enter/Tab** accepts it, and **Escape** dismisses the suggestions. Accepting a suggestion
+does not also submit the parameter.
+
 Expressions are unit-aware: `2 * width + 5 mm`, `angle / 2`, `sqrt(area)`, `1 in + 3 mm`, using
 `+ - * / ^`, parentheses, `sin cos tan asin acos atan atan2 sqrt abs min max floor ceil round mod
 trunc` and unit conversion. A length where an angle is expected (or the other way round) is an

docs/nix.md

@@ -0,0 +1,90 @@
+# SolidCraft with Nix
+
+The flake supports `x86_64-linux` and `aarch64-linux`. Enable Nix's `nix-command`
+and `flakes` experimental features. The committed `flake.lock` pins nixpkgs and
+its Rust toolchain; package evaluation checks that compiler against the Rust
+floor in `Cargo.toml`.
+
+## Run, build or install
+
+Run the current app without installing it:
+
+```sh
+nix run github:bherbruck/solidcraft#solidcraft -- --sample
+```
+
+Inside a checkout, `nix run .` and `nix run .#solidcraft` launch the desktop app.
+`nix run .#cli -- --version` launches the CLI. The legacy `.#solvecraft` app name
+also works. These commands use the flake's exact wrapped binary, rather than an
+older executable already on your shell's `PATH`.
+
+Build without installing:
+
+```sh
+nix build github:bherbruck/solidcraft#solidcraft
+./result/bin/solidcraft --version
+./result/bin/solidcraft --sample
+```
+
+The result contains `solidcraft`, the compatible `solvecraft` binary name, and
+`solvecraft-cli`. **Building does not install a desktop-menu entry.** For a user
+profile installation, run:
+
+```sh
+nix profile install github:bherbruck/solidcraft#solidcraft
+solidcraft --sample
+```
+
+This installs the SolidCraft desktop entry, MIME definition and generated icon
+sizes alongside the commands. NixOS/Home Manager can instead put the flake's
+`packages.${system}.solidcraft` in `environment.systemPackages`/`home.packages`.
+If a non-NixOS desktop does not discover profile-installed launchers, ensure that
+its session includes `~/.nix-profile/share` in `XDG_DATA_DIRS`, then log out and
+back in. The existing `ai.storyteller.solvecraft` desktop/application ID and
+`.solvecraft` design files remain compatible.
+
+Check which executable a plain terminal command would run:
+
+```sh
+type -a solidcraft solvecraft
+readlink -f "$(command -v solidcraft)"
+solidcraft --version
+nix run github:bherbruck/solidcraft#solidcraft -- --version
+```
+
+An unrelated old `solvecraft` executable on `PATH` is not updated by `nix build`.
+Use the flake app or `./result/bin/solidcraft` to verify the package you just built.
+
+## Graphics and file dialogs
+
+The app wrapper includes Wayland, X11, xkbcommon, EGL, Vulkan-loader and D-Bus
+libraries. It exposes `/run/opengl-driver/lib` and
+`/run/opengl-driver/share` so NixOS's graphics drivers and Vulkan manifests are
+discoverable. Enable `hardware.graphics.enable = true` on NixOS and keep the
+system's driver stack consistent with the compositor. File pickers also need a
+working session D-Bus and the desktop's `xdg-desktop-portal` service.
+
+On another distribution, graphics drivers outside the Nix store may need a
+matching [nixGL wrapper](https://github.com/nix-community/nixGL). Follow its
+GPU-specific instructions; a wrapper for a different driver is not a substitute.
+For Intel/Mesa, after building:
+
+```sh
+nix run github:nix-community/nixGL#nixGLIntel -- ./result/bin/solidcraft --sample
+```
+
+If a window is black, first verify that you launched the newly wrapped package
+and that your system exposes a functioning GPU driver. `WGPU_BACKEND=vulkan`
+selects Vulkan for diagnosis; a loader without a usable driver still cannot render.
+OpenGL rendering uses 1x anti-aliasing to avoid the multisampled black-frame failure.
+Vulkan and other backends keep the requested sample count; saved preferences are preserved.
+For older builds, including 0.3.0, set Anti-aliasing to 1x and restart when using OpenGL.
+If that window cannot show the settings dialog, edit only the `msaa` field to `1` in
+`~/.local/share/solvecraft/graphics.json`; preserve any other settings.
+
+## Development shells
+
+`nix develop` supplies runtime libraries and uses the Rust/C toolchain already on
+your `PATH`. `nix develop .#rust` supplies the pinned toolchain, C linker and
+`target/nix` build directory. Both retain the GUI and CLI's existing Cargo package
+names (`solvecraft`, `solvecraft-cli`).