feat: add AppAction enum and Doom Emacs keybinding configuration

18-variant AppAction enum + build_normal_keymap() with hjkl, gg/G, gt/gT,
1-6 tabs, C-d/C-u, SPC leader tree (buffer/help/quit/notifications).

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/claude-agent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/input/action.rs

@@ -0,0 +1,25 @@
+#[derive(Clone, Debug)]
+pub enum AppAction {
+    // Movement
+    MoveUp,
+    MoveDown,
+    FocusLeft,
+    FocusRight,
+    CycleFocus,
+    GotoFirst,
+    GotoLast,
+    HalfPageDown,
+    HalfPageUp,
+
+    // Tabs
+    NextTab,
+    PrevTab,
+    GotoTab(usize),
+
+    // System
+    Quit,
+    Refresh,
+    ShowHelp,
+    ToggleNotifications,
+    Escape,
+}

src/input/keymap.rs

@@ -0,0 +1,61 @@
+use evil_keys::KeyTrie;
+
+use crate::input::action::AppAction;
+
+pub fn build_normal_keymap() -> KeyTrie<AppAction> {
+    let mut t = KeyTrie::new("normal");
+
+    t.bind_desc("j", AppAction::MoveDown, "down").unwrap();
+    t.bind_desc("k", AppAction::MoveUp, "up").unwrap();
+    t.bind_desc("h", AppAction::FocusLeft, "focus left")
+        .unwrap();
+    t.bind_desc("l", AppAction::FocusRight, "focus right")
+        .unwrap();
+    t.bind_desc("Tab", AppAction::CycleFocus, "cycle focus")
+        .unwrap();
+    t.bind_desc("G", AppAction::GotoLast, "last item").unwrap();
+    t.bind_desc("C-d", AppAction::HalfPageDown, "half page down")
+        .unwrap();
+    t.bind_desc("C-u", AppAction::HalfPageUp, "half page up")
+        .unwrap();
+
+    t.group("g", "+goto", |g| {
+        g.bind_desc("g", AppAction::GotoFirst, "first item")?;
+        g.bind_desc("t", AppAction::NextTab, "next tab")?;
+        g.bind_desc("T", AppAction::PrevTab, "prev tab")?;
+        Ok(())
+    })
+    .unwrap();
+
+    for i in 1..=6 {
+        t.bind(&format!("{i}"), AppAction::GotoTab(i - 1)).unwrap();
+    }
+
+    t.group("SPC", "+leader", |g| {
+        g.group("b", "+buffer", |b| {
+            b.bind_desc("l", AppAction::GotoTab(0), "library")?;
+            b.bind_desc("w", AppAction::GotoTab(1), "wanted")?;
+            b.bind_desc("q", AppAction::GotoTab(2), "queue")?;
+            b.bind_desc("h", AppAction::GotoTab(3), "history")?;
+            b.bind_desc("n", AppAction::NextTab, "next")?;
+            b.bind_desc("p", AppAction::PrevTab, "prev")?;
+            Ok(())
+        })?;
+        g.bind_desc("h", AppAction::ShowHelp, "help")?;
+        g.bind_desc("q", AppAction::Quit, "quit")?;
+        g.bind_desc("n", AppAction::ToggleNotifications, "notifications")?;
+        Ok(())
+    })
+    .unwrap();
+
+    t.bind("Esc", AppAction::Escape).unwrap();
+    t.bind("?", AppAction::ShowHelp).unwrap();
+
+    t
+}
+
+pub fn build_insert_keymap() -> KeyTrie<AppAction> {
+    let mut t = KeyTrie::new("insert");
+    t.bind("Esc", AppAction::Escape).unwrap();
+    t
+}

src/input/mod.rs

@@ -0,0 +1,5 @@
+pub mod action;
+pub mod keymap;
+
+pub use action::AppAction;
+pub use keymap::{build_insert_keymap, build_normal_keymap};