fix: satisfy clippy::useless_borrows_in_formatting (unbreaks CI)

[dubadub]

CI on main is broken, and every open PR is red because of it — including a docs-only one. This is the fix.

Cause

The Test workflow installs stable and runs cargo clippy -- -D warnings. Stable has since moved to Rust 1.97, which added useless_borrows_in_formatting. It fires on two pre-existing sites:

• src/server/mod.rs:179 — println!("...{:?}", &state.base_path)
• src/util/cooklang_to_cooklang.rs:118 — &igr.name as a format! argument

Nothing changed in the repo. main's last green run was 1 July; the toolchain moved underneath it. Clippy's failure is the first step in the job, so builds and tests never even run — which is why #367, #368 and #369 all report Test fail despite passing locally.

Change

Drop the two redundant references. No behaviour change: Display/Debug are implemented for both the value and the reference, so the formatted output is identical.

Verification

Reproduced the failure on main with a pinned 1.97 toolchain, then confirmed the fix against the same toolchain CI uses:

• cargo +1.97 clippy --all-targets -- -D warnings — 0 issues (default and --no-default-features)
• cargo +1.97 fmt --check — clean
• cargo +1.97 test — 13 suites pass

Worth merging first — the other PRs cannot show green until this lands.

[claude]

Review

Small, well-scoped fix — verified both hunks against current main.

Correctness

• src/server/mod.rs:179: state.base_path is Utf8PathBuf inside Arc<AppState>; println!("{:?}", ...) only needs &Utf8PathBuf implicitly via Debug::fmt, so dropping the explicit & doesn't move anything. Confirmed state.base_path is still used later (line 188, ServeDir::new(&state.base_path)) — no borrow/move conflict introduced.
• src/util/cooklang_to_cooklang.rs:118: igr is itself &recipe.ingredients[index], so igr.name is a field access through a reference — same reasoning, no behavior change. igr is still used afterward (igr.modifiers(), etc.), consistent with the PR description.

Both match exactly what clippy::useless_borrows_in_formatting (new in Rust 1.97) flags — redundant & on values that already implement Display/Debug and are used in a formatting macro. No semantic change, output is identical.

Code quality / style: Diff is minimal and idiomatic — this is the correct fix rather than suppressing the lint with an #[allow].

Scope: I swept the rest of src/ for the same format!/println! pattern with a leading & on the last arg and didn't find other latent occurrences, so the PR isn't missing sibling fixes.

Tests / CI: No test coverage needed — this is a non-behavioral lint fix. The PR description documents reproduction against a pinned 1.97 toolchain (clippy --all-targets -D warnings, fmt --check, cargo test), which is exactly the right verification for a CI-unblock PR like this.

Security: None applicable — no user input, no I/O behavior change.

No issues found. LGTM — this should merge quickly since (per the PR description) it's blocking green CI for other open PRs.