feat(graphics): default hardware_acceleration to 1 (was 0)

The earlier default of `hardware_acceleration = 0` was set "for maximum
compatibility" but in practice it shipped a severely degraded experience
to every user with a working GPU. Under WebKitGTK software compositing
(what hardware_acceleration=0 forces via WEBKIT_DISABLE_COMPOSITING_MODE
in main.rs:477) mounting any new component takes multiple seconds on
4K / tiled windows — confirmed during the 2026-05-12 perf session where
the same modal that took 2-3s to open under SW comp opened instantly
with HW accel on.

The mitigation logic in `main.rs:482-496` already handles known-broken
configs (NVIDIA-only Wayland forces compositing off; AMD/Intel/hybrid
configs run with compositing enabled). With HW accel = ON as the new
default, that mitigation logic actually runs — previously the nuclear
"off everything" branch at `main.rs:468` was the de-facto path for
every user who hadn't explicitly opted in.

Schema change is non-destructive: `INSERT OR IGNORE` only seeds the
row on first run, so existing users who already have a row keep their
preference. Only fresh installs (and the test environment after
`DELETE FROM graphics_settings`) pick up the new default.

cc

src-tauri/src/config/graphics_settings.rs

@@ -117,12 +117,21 @@ impl GraphicsSettingsStore {
         conn.execute_batch("PRAGMA journal_mode=WAL; PRAGMA synchronous=NORMAL;")
             .map_err(|e| format!("Failed to enable WAL for graphics settings database: {}", e))?;
 
+        // Default hardware_acceleration = 1. Earlier QBZ versions defaulted
+        // to 0 "for maximum compatibility", but WebKitGTK without GPU
+        // compositing is severely degraded (multi-second component mounts
+        // on 4K / tiled windows; observed 2026-05-12 perf session). The
+        // mitigation logic in main.rs already auto-detects NVIDIA-only
+        // Wayland configs and disables compositing for them; for every
+        // other config the GPU path is the better default. Users who
+        // explicitly toggle off in Settings keep their preference (the
+        // INSERT OR IGNORE below only seeds a row that doesn't exist).
         conn.execute_batch(
             "CREATE TABLE IF NOT EXISTS graphics_settings (
                 id INTEGER PRIMARY KEY CHECK (id = 1),
-                hardware_acceleration INTEGER NOT NULL DEFAULT 0
+                hardware_acceleration INTEGER NOT NULL DEFAULT 1
             );
-            INSERT OR IGNORE INTO graphics_settings (id, hardware_acceleration) VALUES (1, 0);",
+            INSERT OR IGNORE INTO graphics_settings (id, hardware_acceleration) VALUES (1, 1);",
         )
         .map_err(|e| format!("Failed to create graphics settings table: {}", e))?;