style: apply rustfmt across bench and core crates

Pure formatting pass - no semantic changes. Mostly long-line reflow,
import statement reordering (alphabetical), and trailing-newline fixes
that had been accumulating in the working tree.

Affected files:
* crates/bench/src/{data_gen,main,mmap_reader,pread_reader,report,runner}.rs
* crates/bench/src/suites/{concurrent,growth,jump,memory,render,rotation,startup}.rs
* crates/core/src/io/{file_reader,index_cache,read_cache}.rs
* crates/core/src/{types.rs, watcher/file_watcher.rs}

crates/bench/src/data_gen.rs

@@ -84,10 +84,8 @@ pub fn generate_growable_file(dir: &Path) -> std::io::Result<PathBuf> {
 /// Append `count` lines to the file
 pub fn append_lines(path: &Path, count: usize) -> std::io::Result<()> {
     let existing_lines = count_existing_lines(path)?;
-    let mut file = BufWriter::with_capacity(
-        64 * 1024,
-        fs::OpenOptions::new().append(true).open(path)?,
-    );
+    let mut file =
+        BufWriter::with_capacity(64 * 1024, fs::OpenOptions::new().append(true).open(path)?);
     for i in 0..count {
         writeln!(
             file,

crates/bench/src/main.rs

@@ -27,8 +27,10 @@ fn main() {
 
     let suites = match args.suites {
         Some(names) => {
-            let parsed: Result<Vec<_>, _> =
-                names.iter().map(|s| s.parse::<log_viewer_bench::runner::Suite>()).collect();
+            let parsed: Result<Vec<_>, _> = names
+                .iter()
+                .map(|s| s.parse::<log_viewer_bench::runner::Suite>())
+                .collect();
             match parsed {
                 Ok(s) => Some(s),
                 Err(e) => {

crates/bench/src/mmap_reader.rs

@@ -7,14 +7,14 @@
 use std::fs::File;
 use std::io::BufReader;
 use std::path::Path;
-use std::sync::atomic::{AtomicBool, AtomicPtr, AtomicU8, Ordering};
 use std::sync::Once;
+use std::sync::atomic::{AtomicBool, AtomicPtr, AtomicU8, Ordering};
 
 use memmap2::{Advice, Mmap, MmapOptions, RemapOptions};
-use nix::sys::signal::{sigaction, SaFlags, SigAction, SigHandler, SigSet, Signal};
+use nix::sys::signal::{SaFlags, SigAction, SigHandler, SigSet, Signal, sigaction};
 
-use crate::line_index::LineIndex;
 use crate::FileReaderBackend;
+use crate::line_index::LineIndex;
 
 // ─── SIGBUS Handler ──────────────────────────────────────────────────────────
 //
@@ -35,7 +35,10 @@ const HANDLER_NONE: u8 = 0;
 const HANDLER_DEFAULT: u8 = 1;
 const HANDLER_IGNORE: u8 = 2;
 const HANDLER_PLAIN: u8 = 3; // extern "C" fn(c_int)
-#[allow(clippy::unseparated_literal_suffix, reason = "clarity: this is the SA_SIGACTION variant")]
+#[allow(
+    clippy::unseparated_literal_suffix,
+    reason = "clarity: this is the SA_SIGACTION variant"
+)]
 const HANDLER_SIGACTION: u8 = 4; // extern "C" fn(c_int, *mut siginfo_t, *mut c_void)
 
 /// Old SIGBUS handler type — raw atomic, async-signal-safe to read.
@@ -107,11 +110,8 @@ extern "C" fn sigbus_handler(
             HANDLER_SIGACTION => {
                 let ptr = OLD_HANDLER_PTR.load(Ordering::Acquire);
                 if !ptr.is_null() {
-                    let f: extern "C" fn(
-                        libc::c_int,
-                        *mut libc::siginfo_t,
-                        *mut std::ffi::c_void,
-                    ) = unsafe { std::mem::transmute(ptr) };
+                    let f: extern "C" fn(libc::c_int, *mut libc::siginfo_t, *mut std::ffi::c_void) =
+                        unsafe { std::mem::transmute(ptr) };
                     f(sig, info, ctx);
                 } else {
                     unsafe { libc::_exit(128 + sig) };

crates/bench/src/pread_reader.rs

@@ -15,8 +15,8 @@ use std::os::unix::fs::FileExt;
 use std::os::unix::io::AsRawFd;
 use std::path::Path;
 
-use crate::line_index::LineIndex;
 use crate::FileReaderBackend;
+use crate::line_index::LineIndex;
 
 const BLOCK_SIZE: usize = 256;
 const CACHE_CHUNK: usize = 4096;
@@ -478,12 +478,19 @@ mod tests {
         let mut reader = PreadReaderPlain::open(&path).unwrap();
         assert_eq!(reader.total_lines(), 3);
         assert_eq!(reader.get_line(0), Some("alpha".to_owned()));
-        assert_eq!(reader.get_line(3), None, "should be out of bounds before append");
+        assert_eq!(
+            reader.get_line(3),
+            None,
+            "should be out of bounds before append"
+        );
 
         // Phase 2: append 2 more lines
         {
             use std::io::Write as _;
-            let mut f = std::fs::OpenOptions::new().append(true).open(&path).unwrap();
+            let mut f = std::fs::OpenOptions::new()
+                .append(true)
+                .open(&path)
+                .unwrap();
             f.write_all(b"delta\nepsilon\n").unwrap();
         }
 

crates/bench/src/report.rs

@@ -145,8 +145,7 @@ pub fn format_report(results: &[BenchmarkResult]) -> String {
 
             let mut mem_rows: Vec<&BenchmarkResult> = category_results.to_vec();
             mem_rows.sort_by(|a, b| {
-                (&a.test_name, &a.backend, &a.variant)
-                    .cmp(&(&b.test_name, &b.backend, &b.variant))
+                (&a.test_name, &a.backend, &a.variant).cmp(&(&b.test_name, &b.backend, &b.variant))
             });
             for r in mem_rows {
                 let variant_label = format!("{} ({})", r.backend, r.variant);
@@ -243,21 +242,60 @@ mod tests {
     #[test]
     fn report_ordering_independent_of_input_order() {
         let set_a = vec![
-            make_result("sequential", "read_1mb", "pread", "default", vec![100, 110, 105]),
-            make_result("sequential", "read_1mb", "mmap", "default", vec![80, 85, 90]),
-            make_result("sequential", "read_4kb", "pread", "default", vec![10, 12, 11]),
+            make_result(
+                "sequential",
+                "read_1mb",
+                "pread",
+                "default",
+                vec![100, 110, 105],
+            ),
+            make_result(
+                "sequential",
+                "read_1mb",
+                "mmap",
+                "default",
+                vec![80, 85, 90],
+            ),
+            make_result(
+                "sequential",
+                "read_4kb",
+                "pread",
+                "default",
+                vec![10, 12, 11],
+            ),
             make_result("sequential", "read_4kb", "mmap", "default", vec![8, 9, 7]),
         ];
 
         let set_b = vec![
             make_result("sequential", "read_4kb", "mmap", "default", vec![8, 9, 7]),
-            make_result("sequential", "read_1mb", "mmap", "default", vec![80, 85, 90]),
-            make_result("sequential", "read_4kb", "pread", "default", vec![10, 12, 11]),
-            make_result("sequential", "read_1mb", "pread", "default", vec![100, 110, 105]),
+            make_result(
+                "sequential",
+                "read_1mb",
+                "mmap",
+                "default",
+                vec![80, 85, 90],
+            ),
+            make_result(
+                "sequential",
+                "read_4kb",
+                "pread",
+                "default",
+                vec![10, 12, 11],
+            ),
+            make_result(
+                "sequential",
+                "read_1mb",
+                "pread",
+                "default",
+                vec![100, 110, 105],
+            ),
         ];
 
         let report_a = format_report(&set_a);
         let report_b = format_report(&set_b);
-        assert_eq!(report_a, report_b, "Reports must be identical regardless of input order");
+        assert_eq!(
+            report_a, report_b,
+            "Reports must be identical regardless of input order"
+        );
     }
 }

crates/bench/src/runner.rs

@@ -154,7 +154,11 @@ mod tests {
             ("concurrent", Suite::Concurrent),
         ];
         for (s, expected_suite) in expected {
-            assert_eq!(Suite::from_str(s).unwrap(), expected_suite, "failed to parse '{s}'");
+            assert_eq!(
+                Suite::from_str(s).unwrap(),
+                expected_suite,
+                "failed to parse '{s}'"
+            );
         }
     }
 

crates/bench/src/suites/concurrent.rs

@@ -1,5 +1,6 @@
 use std::collections::HashMap;
 
+use crate::FileReaderBackend;
 use crate::metrics::MetricsCollector;
 use crate::mmap_reader::{
     MmapReaderPhaseAware, MmapReaderPlain, MmapReaderPopulate, MmapReaderRandom,
@@ -8,7 +9,6 @@ use crate::mmap_reader::{
 use crate::pread_reader::{PreadReaderPlain, PreadReaderRandom, PreadReaderSequential};
 use crate::runner::BenchConfig;
 use crate::types::BenchmarkResult;
-use crate::FileReaderBackend;
 
 pub fn run(config: &BenchConfig) -> Vec<BenchmarkResult> {
     let mut results = Vec::new();

crates/bench/src/suites/growth.rs

@@ -1,12 +1,12 @@
 use std::collections::HashMap;
 
+use crate::FileReaderBackend;
 use crate::data_gen;
 use crate::metrics::MetricsCollector;
 use crate::mmap_reader::MmapReaderPlain;
 use crate::pread_reader::PreadReaderPlain;
 use crate::runner::BenchConfig;
 use crate::types::BenchmarkResult;
-use crate::FileReaderBackend;
 
 pub fn run(config: &BenchConfig) -> Vec<BenchmarkResult> {
     let mut results = Vec::new();

crates/bench/src/suites/jump.rs

@@ -1,6 +1,7 @@
 use std::collections::HashMap;
 
 use super::FRAME_LINES;
+use crate::FileReaderBackend;
 use crate::metrics::MetricsCollector;
 use crate::mmap_reader::{
     MmapReaderPhaseAware, MmapReaderPlain, MmapReaderPopulate, MmapReaderRandom,
@@ -9,7 +10,6 @@ use crate::mmap_reader::{
 use crate::pread_reader::{PreadReaderPlain, PreadReaderRandom, PreadReaderSequential};
 use crate::runner::BenchConfig;
 use crate::types::BenchmarkResult;
-use crate::FileReaderBackend;
 
 pub fn run(config: &BenchConfig) -> Vec<BenchmarkResult> {
     let mut results = Vec::new();

crates/bench/src/suites/memory.rs

@@ -1,5 +1,6 @@
 use std::collections::HashMap;
 
+use crate::FileReaderBackend;
 use crate::metrics::MetricsCollector;
 use crate::mmap_reader::{
     MmapReaderPhaseAware, MmapReaderPlain, MmapReaderPopulate, MmapReaderRandom,
@@ -8,7 +9,6 @@ use crate::mmap_reader::{
 use crate::pread_reader::{PreadReaderPlain, PreadReaderRandom, PreadReaderSequential};
 use crate::runner::BenchConfig;
 use crate::types::BenchmarkResult;
-use crate::FileReaderBackend;
 
 pub fn run(config: &BenchConfig) -> Vec<BenchmarkResult> {
     let mut results = Vec::new();

crates/bench/src/suites/render.rs

@@ -1,6 +1,7 @@
 use std::collections::HashMap;
 
 use super::FRAME_LINES;
+use crate::FileReaderBackend;
 use crate::metrics::MetricsCollector;
 use crate::mmap_reader::{
     MmapReaderPhaseAware, MmapReaderPlain, MmapReaderPopulate, MmapReaderRandom,
@@ -9,7 +10,6 @@ use crate::mmap_reader::{
 use crate::pread_reader::{PreadReaderPlain, PreadReaderRandom, PreadReaderSequential};
 use crate::runner::BenchConfig;
 use crate::types::BenchmarkResult;
-use crate::FileReaderBackend;
 
 pub fn run(config: &BenchConfig) -> Vec<BenchmarkResult> {
     let mut results = Vec::new();
@@ -248,7 +248,11 @@ mod tests {
                 assert!(
                     !ranges_overlap(pos[i].1, pos[j].1),
                     "overlap: {:?} @ {} vs {:?} @ {} (total={})",
-                    pos[i].0, pos[i].1, pos[j].0, pos[j].1, total
+                    pos[i].0,
+                    pos[i].1,
+                    pos[j].0,
+                    pos[j].1,
+                    total
                 );
             }
         }
@@ -269,7 +273,10 @@ mod tests {
                 assert!(
                     !ranges_overlap(pos[i].1, pos[j].1),
                     "overlap at total=104: {:?} @ {} vs {:?} @ {}",
-                    pos[i].0, pos[i].1, pos[j].0, pos[j].1
+                    pos[i].0,
+                    pos[i].1,
+                    pos[j].0,
+                    pos[j].1
                 );
             }
         }
@@ -283,7 +290,10 @@ mod tests {
                 assert!(
                     !ranges_overlap(pos[i].1, pos[j].1),
                     "overlap at total=105: {:?} @ {} vs {:?} @ {}",
-                    pos[i].0, pos[i].1, pos[j].0, pos[j].1
+                    pos[i].0,
+                    pos[i].1,
+                    pos[j].0,
+                    pos[j].1
                 );
             }
         }

crates/bench/src/suites/rotation.rs

@@ -1,12 +1,12 @@
 use std::collections::HashMap;
 
+use crate::FileReaderBackend;
 use crate::data_gen;
 use crate::metrics::MetricsCollector;
 use crate::mmap_reader::{self, MmapReaderPlain};
 use crate::pread_reader::PreadReaderPlain;
 use crate::runner::BenchConfig;
 use crate::types::BenchmarkResult;
-use crate::FileReaderBackend;
 
 pub fn run(config: &BenchConfig) -> Vec<BenchmarkResult> {
     let mut results = Vec::new();

crates/bench/src/suites/startup.rs

@@ -1,6 +1,7 @@
 use std::collections::HashMap;
 use std::path::Path;
 
+use crate::FileReaderBackend;
 use crate::metrics::MetricsCollector;
 use crate::mmap_reader::{
     MmapReaderPhaseAware, MmapReaderPlain, MmapReaderPopulate, MmapReaderRandom,
@@ -9,7 +10,6 @@ use crate::mmap_reader::{
 use crate::pread_reader::{PreadReaderPlain, PreadReaderRandom, PreadReaderSequential};
 use crate::runner::BenchConfig;
 use crate::types::BenchmarkResult;
-use crate::FileReaderBackend;
 
 pub fn run(config: &BenchConfig) -> Vec<BenchmarkResult> {
     let mut results = Vec::new();