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_engine/src/assets/svg_loader.rs

@@ -192,7 +192,7 @@ fn shared_fontdb() -> Arc<fontdb::Database> {
 fn bundled_font_resolver() -> usvg::FontResolver<'static> {
     use usvg::FontResolver;
 
-    usvg::FontResolver {
+    FontResolver {
         select_font: Box::new(|_font, db| db.faces().next().map(|face| face.id)),
         select_fallback: FontResolver::default_fallback_selector(),
     }
@@ -282,7 +282,7 @@ mod tests {
     /// tightens.
     #[test]
     fn settings_satisfies_loader_bounds() {
-        fn assert_loader_settings<T: Default + serde::Serialize + serde::de::DeserializeOwned>() {}
+        fn assert_loader_settings<T: Default + Serialize + serde::de::DeserializeOwned>() {}
         assert_loader_settings::<SvgLoaderSettings>();
     }
 }