shell: ^C cancels the line / aborts streams, ^D = EOF → poweroff

- ps2: Ctrl+C and Ctrl+D are now KeyEvents (ctrl modifier + c/d map);
  other Ctrl+key combos are swallowed
- shell read_line: ^C clears the line and echoes '^C' (bash-style),
  ^D on an empty line echoes '^D' and shuts down (EOF), ^D with text
  on the line is ignored
- cat/hexdump stream incrementally (was: build whole string then print)
  and check for ^C between chunks, so a running dump can be aborted
- verified in QEMU: line cancel, standalone interrupt, ^C aborts an
  infinite 'cat /dev/zero' stream, ^D powers off

2 files changed, 33 insertions, 10 deletions

diff --git a/rsnix/src/fs.rs b/rsnix/src/fs.rs
index 56820bb..95a84bf 100644
--- a/rsnix/src/fs.rs
+++ b/rsnix/src/fs.rs
@@ -15,14 +15,14 @@
 
 extern crate alloc;
 
-use alloc::boxed::Box;
-use alloc::string::String;
-use alloc::vec::Vec;
 use crate::gop;
 use crate::memory;
 use crate::pci;
 use crate::rtc;
 use crate::serial;
+use alloc::boxed::Box;
+use alloc::string::String;
+use alloc::vec::Vec;
 
 /// /dev/mem covers the low physical-memory window (identity-mapped RAM).
 pub const MEM_WINDOW: u64 = 64 * 1024;
@@ -96,9 +96,24 @@ pub fn init() -> (usize, usize) {
     let _tmp = add("tmp", Some(root), FileType::Dir, NodeData::Dir(Vec::new()));
     let etc = add("etc", Some(root), FileType::Dir, NodeData::Dir(Vec::new()));
 
-    add("mem", Some(dev), FileType::Char, NodeData::Char(CharDevice::Mem));
-    add("rtc", Some(dev), FileType::Char, NodeData::Char(CharDevice::Rtc));
-    add("pci", Some(dev), FileType::Char, NodeData::Char(CharDevice::Pci));
+    add(
+        "mem",
+        Some(dev),
+        FileType::Char,
+        NodeData::Char(CharDevice::Mem),
+    );
+    add(
+        "rtc",
+        Some(dev),
+        FileType::Char,
+        NodeData::Char(CharDevice::Rtc),
+    );
+    add(
+        "pci",
+        Some(dev),
+        FileType::Char,
+        NodeData::Char(CharDevice::Pci),
+    );
     add(
         "version",
         Some(dev),
@@ -146,10 +161,7 @@ pub fn init() -> (usize, usize) {
         ),
     );
 
-    let dirs = nodes()
-        .iter()
-        .filter(|n| n.kind == FileType::Dir)
-        .count();
+    let dirs = nodes().iter().filter(|n| n.kind == FileType::Dir).count();
     let files = nodes().len() - dirs;
     (dirs, files)
 }
diff --git a/rsnix/src/ps2.rs b/rsnix/src/ps2.rs
index 477d146..1b10b3b 100644
--- a/rsnix/src/ps2.rs
+++ b/rsnix/src/ps2.rs
@@ -22,6 +22,8 @@ pub enum KeyEvent {
     Backspace,
     Tab,
     Escape,
+    CtrlC,
+    CtrlD,
     ArrowUp,
     ArrowDown,
     ArrowLeft,
@@ -304,6 +306,15 @@ fn process_byte(byte: u8) -> Option<KeyEvent> {
                     ch.to_ascii_uppercase()
                 };
             }
+            // Ctrl+letter — the shell uses ^C (interrupt) and ^D (EOF).
+            let ctrl = state.modifiers & (MOD_LCTRL | MOD_RCTRL) != 0;
+            if ctrl {
+                return match ch.to_ascii_lowercase() {
+                    b'c' => Some(KeyEvent::CtrlC),
+                    b'd' => Some(KeyEvent::CtrlD),
+                    _ => None, // swallow other Ctrl+key combinations
+                };
+            }
             if ch != 0 {
                 Some(KeyEvent::Char(ch as char))
             } else {