✨ Add mouse interaction and enhanced file navigation to Studio TUI

Implement comprehensive mouse support for the Studio TUI with double-click
detection, drag selection in code views, and click-to-navigate in file trees
across all modes (Explore, Commit, Review, PR).

Key changes:
- Add vim-style visual selection mode ('v') with multi-line copy support
- Display all tracked repository files in Explore mode instead of just
  changed files
- Add 'A' toggle in Commit mode to switch between changed/all files view
- Improve file tree icons with Unicode symbols for better visual clarity
- Fix mouse scroll handling across all Studio modes and panels
- Add get_all_tracked_files() to git layer for full repo file listing

Author: hyperb1iss

src/git/files.rs

@@ -242,6 +242,52 @@ pub fn get_untracked_files(repo: &Repository) -> Result<Vec<String>> {
     Ok(untracked)
 }
 
+/// Gets all tracked files in the repository (from HEAD tree + index)
+///
+/// This returns all files that are tracked by git, which includes:
+/// - Files committed in HEAD
+/// - Files staged in the index (including newly added files)
+///
+/// # Returns
+///
+/// A Result containing a Vec of file paths or an error.
+pub fn get_all_tracked_files(repo: &Repository) -> Result<Vec<String>> {
+    log_debug!("Getting all tracked files");
+    let mut files = std::collections::HashSet::new();
+
+    // Get files from HEAD tree
+    if let Ok(head) = repo.head()
+        && let Ok(tree) = head.peel_to_tree()
+    {
+        tree.walk(git2::TreeWalkMode::PreOrder, |dir, entry| {
+            if entry.kind() == Some(git2::ObjectType::Blob) {
+                let path = if dir.is_empty() {
+                    entry.name().unwrap_or("").to_string()
+                } else {
+                    format!("{}{}", dir, entry.name().unwrap_or(""))
+                };
+                if !path.is_empty() {
+                    files.insert(path);
+                }
+            }
+            git2::TreeWalkResult::Ok
+        })?;
+    }
+
+    // Also include files from the index (staged files, including new files)
+    let index = repo.index()?;
+    for entry in index.iter() {
+        let path = String::from_utf8_lossy(&entry.path).to_string();
+        files.insert(path);
+    }
+
+    let mut result: Vec<_> = files.into_iter().collect();
+    result.sort();
+
+    log_debug!("Found {} tracked files", result.len());
+    Ok(result)
+}
+
 /// Gets the number of commits ahead and behind the upstream tracking branch
 ///
 /// # Returns

src/git/repository.rs

@@ -2,8 +2,8 @@ use crate::config::Config;
 use crate::context::{CommitContext, RecentCommit, StagedFile};
 use crate::git::commit::{self, CommitResult};
 use crate::git::files::{
-    RepoFilesInfo, get_ahead_behind, get_file_statuses, get_unstaged_file_statuses,
-    get_untracked_files,
+    RepoFilesInfo, get_ahead_behind, get_all_tracked_files, get_file_statuses,
+    get_unstaged_file_statuses, get_untracked_files,
 };
 use crate::git::utils::is_inside_work_tree;
 use crate::log_debug;
@@ -856,6 +856,12 @@ impl GitRepo {
         get_untracked_files(&repo)
     }
 
+    /// Get all tracked files in the repository (from HEAD + index)
+    pub fn get_all_tracked_files(&self) -> Result<Vec<String>> {
+        let repo = self.open_repo()?;
+        get_all_tracked_files(&repo)
+    }
+
     /// Get ahead/behind counts relative to upstream tracking branch
     ///
     /// Returns (ahead, behind) tuple, or (0, 0) if no upstream is configured

src/studio/app.rs

@@ -160,6 +160,18 @@ impl CodeViewState {
     pub fn is_loaded(&self) -> bool {
         self.current_file.is_some()
     }
+
+    /// Select a line by visible row (for mouse clicks)
+    /// Returns true if selection changed
+    pub fn select_by_row(&mut self, row: usize) -> bool {
+        let target_line = self.scroll_offset + row + 1; // Convert to 1-indexed
+        if target_line <= self.lines.len() && target_line != self.selected_line {
+            self.selected_line = target_line;
+            true
+        } else {
+            false
+        }
+    }
 }
 
 // ═══════════════════════════════════════════════════════════════════════════════

src/studio/components/code_view.rs

@@ -452,6 +452,47 @@ impl FileTreeState {
     pub fn selected_index(&self) -> usize {
         self.selected
     }
+
+    /// Select an item by visible row (for mouse clicks)
+    /// Returns true if selection changed, false otherwise
+    pub fn select_by_row(&mut self, row: usize) -> bool {
+        let flat_len = self.flat_view().len();
+        let target_index = self.scroll_offset + row;
+
+        if target_index < flat_len && target_index != self.selected {
+            self.selected = target_index;
+            true
+        } else {
+            false
+        }
+    }
+
+    /// Check if the clicked row matches the currently selected item
+    /// Used for double-click detection
+    pub fn is_row_selected(&self, row: usize) -> bool {
+        let target_index = self.scroll_offset + row;
+        target_index == self.selected
+    }
+
+    /// Handle mouse click at a specific row within the visible area.
+    /// Returns a tuple of (`selection_changed`, `is_directory`) for the caller to handle.
+    pub fn handle_click(&mut self, row: usize) -> (bool, bool) {
+        let flat_len = self.flat_view().len();
+        let target_index = self.scroll_offset + row;
+
+        if target_index >= flat_len {
+            return (false, false);
+        }
+
+        let was_selected = target_index == self.selected;
+        let is_dir = self.flat_cache.get(target_index).is_some_and(|e| e.is_dir);
+
+        if !was_selected {
+            self.selected = target_index;
+        }
+
+        (!was_selected, is_dir)
+    }
 }
 
 /// Helper to insert a path into the tree structure
@@ -576,21 +617,21 @@ pub fn render_file_tree(
 fn render_entry(entry: &FlatEntry, is_selected: bool, width: usize) -> Line<'static> {
     let indent = "  ".repeat(entry.depth);
 
-    // Icon (use ASCII for consistent width)
+    // Icon with nice Unicode symbols
     let icon = if entry.is_dir {
-        if entry.is_expanded { "v" } else { ">" }
+        if entry.is_expanded { "▾" } else { "▸" }
     } else {
         get_file_icon(&entry.name)
     };
 
-    // Git status indicator (use ASCII for consistent width)
+    // Git status indicator with Unicode symbols
     let status_indicator = match entry.git_status {
-        FileGitStatus::Staged => "+",
-        FileGitStatus::Modified => "*",
-        FileGitStatus::Untracked => "?",
-        FileGitStatus::Deleted => "x",
-        FileGitStatus::Renamed => "r",
-        FileGitStatus::Conflict => "!",
+        FileGitStatus::Staged => "●",
+        FileGitStatus::Modified => "◐",
+        FileGitStatus::Untracked => "◌",
+        FileGitStatus::Deleted => "✕",
+        FileGitStatus::Renamed => "➜",
+        FileGitStatus::Conflict => "⚠",
         FileGitStatus::Normal => " ",
     };
     let status_style = entry.git_status.style();
@@ -673,23 +714,83 @@ fn truncate_to_width(s: &str, max_width: usize) -> String {
     result
 }
 
-/// Get icon for file based on extension (ASCII-only for consistent width)
+/// Get icon for file based on extension (Unicode symbols, no emoji)
 fn get_file_icon(name: &str) -> &'static str {
+    // Check for special filenames first
+    let lower_name = name.to_lowercase();
+    if lower_name == "cargo.toml" || lower_name == "cargo.lock" {
+        return "◫";
+    }
+    if lower_name.starts_with("readme") {
+        return "◈";
+    }
+    if lower_name.starts_with("license") {
+        return "§";
+    }
+    if lower_name.starts_with(".git") {
+        return "⊙";
+    }
+    if lower_name == "dockerfile" || lower_name.starts_with("docker-compose") {
+        return "◲";
+    }
+    if lower_name == "makefile" {
+        return "⚙";
+    }
+
     let ext = name.rsplit('.').next().unwrap_or("");
     match ext.to_lowercase().as_str() {
-        "rs" => "#",
-        "toml" => "=",
-        "md" => "m",
-        "json" => "j",
-        "yaml" | "yml" => "y",
-        "js" | "jsx" => "J",
-        "ts" | "tsx" => "T",
-        "py" => "p",
-        "go" => "g",
-        "sh" | "bash" | "zsh" => "$",
-        "lock" => "L",
-        "gitignore" => ".",
-        "dockerfile" => "D",
-        _ => "-",
+        // Rust
+        "rs" => "●",
+        // Config files
+        "toml" => "⚙",
+        "yaml" | "yml" => "⚙",
+        "json" => "◇",
+        "xml" => "◇",
+        "ini" | "cfg" | "conf" => "⚙",
+        // Documentation
+        "md" | "mdx" => "◈",
+        "txt" => "≡",
+        "pdf" => "▤",
+        // Web
+        "html" | "htm" => "◊",
+        "css" | "scss" | "sass" | "less" => "◊",
+        "js" | "mjs" | "cjs" => "◆",
+        "jsx" => "◆",
+        "ts" | "mts" | "cts" => "◇",
+        "tsx" => "◇",
+        "vue" => "◊",
+        "svelte" => "◊",
+        // Programming languages
+        "py" | "pyi" => "◈",
+        "go" => "◈",
+        "rb" => "◈",
+        "java" | "class" | "jar" => "◈",
+        "kt" | "kts" => "◈",
+        "swift" => "◈",
+        "c" | "h" => "○",
+        "cpp" | "cc" | "cxx" | "hpp" | "hxx" => "○",
+        "cs" => "◈",
+        "php" => "◈",
+        "lua" => "◈",
+        "r" => "◈",
+        "sql" => "◫",
+        // Shell
+        "sh" | "bash" | "zsh" | "fish" => "▷",
+        "ps1" | "psm1" => "▷",
+        // Data
+        "csv" => "◫",
+        "db" | "sqlite" | "sqlite3" => "◫",
+        // Images
+        "png" | "jpg" | "jpeg" | "gif" | "svg" | "ico" | "webp" => "◧",
+        // Archives
+        "zip" | "tar" | "gz" | "rar" | "7z" => "▣",
+        // Lock files
+        "lock" => "◉",
+        // Git
+        "gitignore" | "gitattributes" | "gitmodules" => "⊙",
+        // Env
+        "env" | "env.local" | "env.development" | "env.production" => "◉",
+        // Default
+        _ => "◦",
     }
 }

src/studio/components/file_tree.rs

@@ -127,6 +127,22 @@ fn handle_files_key(state: &mut StudioState, key: KeyEvent) -> Vec<SideEffect> {
         // Unstage all files
         KeyCode::Char('U') => vec![SideEffect::GitUnstageAll],
 
+        // Toggle between changed files and all tracked files
+        KeyCode::Char('A') => {
+            state.modes.commit.show_all_files = !state.modes.commit.show_all_files;
+            let mode = if state.modes.commit.show_all_files {
+                "all files"
+            } else {
+                "changed files"
+            };
+            state.notify(crate::studio::state::Notification::info(format!(
+                "Showing: {}",
+                mode
+            )));
+            state.mark_dirty();
+            vec![SideEffect::RefreshGitStatus]
+        }
+
         _ => vec![],
     }
 }