Tooling: declare rustfmt + clippy as required toolchain components

Pinning `apps/desktop/rust-toolchain.toml` to a specific channel
without a `components` line tells rustup to install only the minimal
profile (rustc + cargo + rust-std). CI scripts then invoke
`cargo fmt --check` and `cargo clippy` and trip on missing components —
every Rust job on a fresh runner has been failing at the rustfmt step
since the channel pin landed.

Add `components = ["rustfmt", "clippy"]` so the runner installs them
automatically alongside the pinned channel. Devs with local rustup
configs that already include rustfmt are unaffected (rustup honours the
declaration whether the components are already present or not).

Author: vdavid

apps/desktop/rust-toolchain.toml

@@ -3,3 +3,9 @@
 # A compromised rustc release would land transparently otherwise. Bump
 # deliberately, with a few days between Rust's release and our pin update.
 channel = "1.95.0"
+# rustup installs only the minimal profile for a pinned channel by default
+# (rustc + cargo + rust-std). CI invokes `cargo fmt` and `cargo clippy`, both
+# of which need their respective components installed. Declare them here so
+# the runner picks them up automatically — without this, every CI Rust job
+# fails at the rustfmt step.
+components = ["rustfmt", "clippy"]