fix: correct drifted citations at commit f53b654

- traits.md: iterator.rs anchor L76→L42 (pub const trait Iterator)
- traits.md: deref.rs anchor L60→L139 (pub const trait Deref)
- error-handling.md: fix variant names CliError::Io→IoError, Parse→ParseError
  to match actual stdlib doc example at convert/mod.rs:557
- concurrency.md: mutex.rs and rwlock.rs moved to sync/poison/ subtree
  (3 link updates: mutex×2, rwlock×1)

patterns/concurrency.md

@@ -86,7 +86,7 @@ thread::spawn(move || {
 
 ### Source:
 
-[library/std/src/sync/mutex.rs](https://github.com/rust-lang/rust/blob/f53b654a8882fd5fc036c4ca7a4ff41ce32497a6/library/std/src/sync/mutex.rs), [library/alloc/src/sync.rs](https://github.com/rust-lang/rust/blob/f53b654a8882fd5fc036c4ca7a4ff41ce32497a6/library/alloc/src/sync.rs)
+[library/std/src/sync/poison/mutex.rs](https://github.com/rust-lang/rust/blob/f53b654a8882fd5fc036c4ca7a4ff41ce32497a6/library/std/src/sync/poison/mutex.rs), [library/alloc/src/sync.rs](https://github.com/rust-lang/rust/blob/f53b654a8882fd5fc036c4ca7a4ff41ce32497a6/library/alloc/src/sync.rs)
 
 ```rust
 use std::sync::{Arc, Mutex};
@@ -177,7 +177,7 @@ async fn good(data: Arc<Mutex<Vec<i32>>>) {
 
 ### Source:
 
-[library/std/src/sync/rwlock.rs](https://github.com/rust-lang/rust/blob/f53b654a8882fd5fc036c4ca7a4ff41ce32497a6/library/std/src/sync/rwlock.rs)
+[library/std/src/sync/poison/rwlock.rs](https://github.com/rust-lang/rust/blob/f53b654a8882fd5fc036c4ca7a4ff41ce32497a6/library/std/src/sync/poison/rwlock.rs)
 
 ```rust
 use std::sync::RwLock;
@@ -629,7 +629,7 @@ per-thread caches, buffers, and RNG state.
 
 ### Source:
 
-[library/std/src/sync/mutex.rs](https://github.com/rust-lang/rust/blob/f53b654a8882fd5fc036c4ca7a4ff41ce32497a6/library/std/src/sync/mutex.rs)
+[library/std/src/sync/poison/mutex.rs](https://github.com/rust-lang/rust/blob/f53b654a8882fd5fc036c4ca7a4ff41ce32497a6/library/std/src/sync/poison/mutex.rs)
 
 ```rust
 let mutex = Arc::new(Mutex::new(0));

patterns/error-handling.md

@@ -266,12 +266,12 @@ impl std::error::Error for ConnectError {
 // library/core/src/convert/mod.rs:557
 impl From<io::Error> for CliError {
     fn from(error: io::Error) -> Self {
-        CliError::Io(error)
+        CliError::IoError(error)
     }
 }
 impl From<num::ParseIntError> for CliError {
     fn from(error: num::ParseIntError) -> Self {
-        CliError::Parse(error)
+        CliError::ParseError(error)
     }
 }
 ```

patterns/traits.md

@@ -15,7 +15,7 @@ impls, 895 Iterator impls, 269 Display impls, 226 Default impls.
 
 ### Source:
 
-[library/core/src/iter/traits/iterator.rs#L76](https://github.com/rust-lang/rust/blob/f53b654a8882fd5fc036c4ca7a4ff41ce32497a6/library/core/src/iter/traits/iterator.rs#L76)
+[library/core/src/iter/traits/iterator.rs#L42](https://github.com/rust-lang/rust/blob/f53b654a8882fd5fc036c4ca7a4ff41ce32497a6/library/core/src/iter/traits/iterator.rs#L42)
 
 ```rust
 // library/core/src/iter/traits/iterator.rs
@@ -422,7 +422,7 @@ let first_10: Vec<u64> = Fibonacci { a: 0, b: 1 }.take(10).collect();
 
 ### Source:
 
-[library/core/src/ops/deref.rs#L60](https://github.com/rust-lang/rust/blob/f53b654a8882fd5fc036c4ca7a4ff41ce32497a6/library/core/src/ops/deref.rs#L60)
+[library/core/src/ops/deref.rs#L139](https://github.com/rust-lang/rust/blob/f53b654a8882fd5fc036c4ca7a4ff41ce32497a6/library/core/src/ops/deref.rs#L139)
 
 ```rust
 pub trait Deref {