fix: eliminate clippy warnings (#2036)

using clippy 0.1.91 (898aff704d 2025-08-14), but some warnings already
exist in the latest stable version
mostly about elided lifetime and if-chain

only remaining warnings:
```
warning: struct `HashRepr` is never constructed
   --> crates\tinymist-query\src\tests.rs:462:12
    |
462 | pub struct HashRepr<T>(pub T);
    |            ^^^^^^^^
    |
    = note: `#[warn(dead_code)]` on by default

warning: a method with this name may be added to the standard library in the future
   --> crates\tinymist\src\actor\editor.rs:103:30
    |
103 | ...                   .map_or_default(|fid| unix_slash(fid.vpath().as_rooted_path()));
    |                        ^^^^^^^^^^^^^^
    |
    = warning: once this associated item is added to the standard library, the ambiguity may cause an error or change in behavior!
    = note: for more information, see issue #48919 <https://github.com/rust-lang/rust/issues/48919>
    = help: call with fully qualified syntax `typst::typst_utils::OptionExt::map_or_default(...)` to keep using the current method
    = note: `#[warn(unstable_name_collisions)]` on by default
help: add `#![feature(result_option_map_or_default)]` to the crate attributes to enable `std::option::Option::<T>::map_or_default`
   --> crates\tinymist\src\lib.rs:3:1
    |
  3 + #![feature(result_option_map_or_default)]
    |
```

crates/tinymist-query/src/analysis/global.rs

@@ -420,7 +420,7 @@ impl LocalContext {
     }
 
     /// Fork a new context for searching in the workspace.
-    pub fn fork_for_search(&mut self) -> SearchCtx {
+    pub fn fork_for_search(&mut self) -> SearchCtx<'_> {
         SearchCtx {
             ctx: self,
             searched: Default::default(),