chore: add pedantic workspace lints (#90)

Add [workspace.lints.rust] and wire each member crate up with
[lints] workspace = true:

  unsafe_code = "deny"        (forbid would break the Android JNI build)
  single_use_lifetimes = "warn"
  trivial_casts = "warn"
  unused_lifetimes = "warn"
  unused_qualifications = "warn"
  variant_size_differences = "warn"
  unexpected_cfgs = "warn"

unsafe_code is "deny" rather than the issue's "forbid" so the three
Android JNI FFI modules (android_keystore, android_clipboard, safe_area)
can opt back in with a scoped #![allow(unsafe_code)] — forbid cannot be
locally overridden. Pure crates carry no unsafe and stay clean.

Clean up the warnings the new lints surface:
- 150ish unused_qualifications removed via `cargo fix` (purely syntactic
  redundant-path-prefix removals).
- table_plugin: the TABLE_COLOUR import was #[cfg(test)]-gated while the
  camera clear-colour used the fully-qualified path; unqualifying it left
  a non-test build with no import. Made the import unconditional instead.
- assets/sources: the `as &[u8]` casts in embed_*_svg! coerce each
  fixed-size &[u8; N] to a uniform slice so the tuples fit the
  &[(&str, &[u8])] arrays — load-bearing, so scoped #[allow(trivial_casts)].

Workspace clippy -D warnings and the full test suite pass. Android build
not compiled here (needs the NDK; built separately per CLAUDE.md §15) —
the deny + scoped-allow keeps the JNI unsafe blocks legal.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

solitaire_app/Cargo.toml

@@ -99,3 +99,6 @@ icon = "@mipmap/ic_launcher"
 # in portrait orientation. Remove (or add a landscape layout) before
 # enabling auto-rotate.
 orientation = "portrait"
+
+[lints]
+workspace = true

solitaire_app/src/lib.rs

@@ -144,7 +144,7 @@ fn build_app_with_settings(
                     // Android windows always fill the screen; max_width/max_height
                     // default to 0.0, which panics Bevy's clamp when min > max.
                     #[cfg(not(target_os = "android"))]
-                    resize_constraints: bevy::window::WindowResizeConstraints {
+                    resize_constraints: WindowResizeConstraints {
                         min_width: 800.0,
                         min_height: 600.0,
                         ..default()
@@ -166,7 +166,7 @@ fn build_app_with_settings(
             // default makes it walk *out* of the APK's assets root and
             // all loads fail silently — which is what produced the
             // solid-red card-back fallback in the v0.22.3 screenshot.
-            .set(bevy::asset::AssetPlugin {
+            .set(AssetPlugin {
                 #[cfg(not(target_os = "android"))]
                 file_path: "../assets".to_string(),
                 ..default()