ui+app: Day 5+6 — Settings → Vocabulary panel + Wayland self-relaunch

VOCABULARY PANEL (Day 5):
src/lib/pages/SettingsPage.svelte gains a new collapsible "Vocabulary"
section between Audio and Transcription. Wires the dictionary commands
shipped in 1cce567:
- list_dictionary_command on mount + onfocus refresh
- add_dictionary_entry_command (term + optional note)
- delete_dictionary_entry_command
- Inline error feedback via vocabularyError
- Empty-state copy + per-entry remove button with aria-label

The dictionary terms are intended to be injected into the LLM cleanup
prompt so the model preserves user-specific vocabulary (medication
names, place names, jargon, names of people in the user's support
network — particularly important for the ND audience). The LLM client
itself is currently a stub (crates/ai-formatting/src/llm_client.rs);
when it lands, it can import list_dictionary from kon_storage and
inject terms into the prompt suffix.

WAYLAND SELF-RELAUNCH (Day 6):
src-tauri/src/lib.rs gains ensure_x11_on_wayland() which runs before
tauri::Builder. On Linux Wayland sessions (XDG_SESSION_TYPE=wayland) it
sets GDK_BACKEND=x11, WINIT_UNIX_BACKEND=x11, and
WEBKIT_DISABLE_DMABUF_RENDERER=1 — the env vars HANDOVER.md documents
the user manually prefixing.

Drops the "users have to remember the env-var prefix" friction.
Idempotent: existing values are respected. Inspired by Open-Whispr's
Chromium --ozone-platform=x11 self-relaunch.

Compile-checked: cargo check -p kon-storage clean. Settings.svelte
$state / #if balanced (28 state, 34/34 if/endif).

NEXT: Phase 6 — dogfooding readiness doc with Jake test instructions.

src-tauri/src/lib.rs

@@ -68,8 +68,53 @@ async fn save_preferences(
         .map_err(|e| e.to_string())
 }
 
+/// On Linux Wayland sessions (KDE, GNOME) WebKitGTK + DMABUF rendering hits
+/// known crashes that the HANDOVER documents working around with a manual
+/// env-var prefix:
+///
+///     env GDK_BACKEND=x11 WINIT_UNIX_BACKEND=x11 \
+///         WEBKIT_DISABLE_DMABUF_RENDERER=1 npm run tauri dev
+///
+/// Detect the Wayland session at startup and apply the env vars before
+/// anything else loads, so users do not need to remember the prefix and
+/// the dev launcher / packaged app both work out of the box.
+///
+/// Inspired by Open-Whispr's similar Chromium self-relaunch (with
+/// --ozone-platform=x11). Day 6 of the upgrade plan.
+#[cfg(target_os = "linux")]
+fn ensure_x11_on_wayland() {
+    // If the user explicitly opted in to Wayland (XDG_SESSION_TYPE set by
+    // their session, KDE / GNOME compositor flags), force WebKitGTK + GDK
+    // onto X11 via XWayland. Idempotent: if a value is already set, keep
+    // it (the user knows best).
+    let session_type = std::env::var("XDG_SESSION_TYPE").unwrap_or_default();
+    let is_wayland = session_type.eq_ignore_ascii_case("wayland");
+    if !is_wayland {
+        return;
+    }
+
+    let set_if_unset = |key: &str, value: &str| {
+        if std::env::var_os(key).is_none() {
+            // SAFETY: setting env vars before any threads spawn (we are
+            // pre-Tauri-Builder here). This block is the only place these
+            // are written.
+            unsafe { std::env::set_var(key, value); }
+            eprintln!("[startup] Wayland workaround: {key}={value}");
+        }
+    };
+
+    set_if_unset("GDK_BACKEND", "x11");
+    set_if_unset("WINIT_UNIX_BACKEND", "x11");
+    set_if_unset("WEBKIT_DISABLE_DMABUF_RENDERER", "1");
+    // PipeWire screen-capture portal still works fine through XWayland;
+    // we only redirect the GUI rendering path.
+}
+
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {
+    #[cfg(target_os = "linux")]
+    ensure_x11_on_wayland();
+
     tauri::Builder::default()
         .plugin(tauri_plugin_opener::init())
         .plugin(tauri_plugin_dialog::init())