Cas/monaco diffs

apps/native/.storybook/mocks/tauri-runtime.ts

@@ -262,6 +262,14 @@ export const storybookDarwinAPI = {
     cached: async () => baseGitStatus(),
     commit: async () => ({ hash: "mock123", evolveState: baseEvolveState() }),
     stash: async () => okResult(),
+    fileDiffContents: async (_filenames: string[]) => ({}),
+    stageAll: async () => undefined,
+    unstageAll: async () => undefined,
+    restoreAll: async () => undefined,
+    checkoutNewBranch: async (branchName: string) => ({ ok: true, branch: branchName }),
+    checkoutBranch: async () => undefined,
+    checkoutMainBranch: async () => undefined,
+    mergeBranch: async () => undefined,
   },
   darwin: {
     evolve: async () => ({

apps/native/.storybook/vitest.setup.ts

@@ -31,7 +31,19 @@ function normalizeSnapshotRoot(root: Element): string {
     editor.appendChild(placeholder);
   }
 
-  return normalizeAnimations(clone.innerHTML);
+  for (const editor of clone.querySelectorAll(".monaco-diff-editor, .monaco-editor")) {
+    editor.replaceChildren();
+    const placeholder = document.createElement("div");
+    placeholder.setAttribute("data-slot", "monaco-editor-placeholder");
+    editor.appendChild(placeholder);
+  }
+
+  let html = normalizeAnimations(clone.innerHTML);
+  // Monaco assigns auto-incrementing model IDs that vary by test-suite order.
+  html = html.replace(/inmemory:\/\/model\/\d+/g, "inmemory://model/N");
+  // data-keybinding-context values are similarly auto-incremented.
+  html = html.replace(/data-keybinding-context="\d+"/g, 'data-keybinding-context="N"');
+  return html;
 }
 
 // Automatically snapshot every story after it renders

apps/native/package.json

@@ -67,10 +67,12 @@
     "cmdk": "^1.1.1",
     "execa": "^9.6.0",
     "lucide-react": "^1.14.0",
+    "@monaco-editor/react": "^4.7.0",
     "monaco-editor": "^0.55.1",
     "monaco-editor-textmate": "^4.0.0",
     "monaco-textmate": "^3.0.1",
     "motion": "^12.35.2",
+    "onigasm": "^2.2.5",
     "react": "^19.2.3",
     "react-dom": "^19.1.0",
     "react-icons": "^5.5.0",

apps/native/src-tauri/examples/specta_gen_ts.rs

@@ -66,6 +66,7 @@ fn main() {
         .register::<shared_types::RollbackResult>()
         .register::<shared_types::SetDirResult>()
         .register::<shared_types::UiPrefs>()
+        .register::<shared_types::FileDiffContents>()
         .register::<shared_types::UiPrefsUpdate>()
         .register::<shared_types::OkResult>()
         .register::<shared_types::NixCheckResult>()

apps/native/src-tauri/src/commands/git.rs

@@ -4,6 +4,31 @@ use crate::storage::store;
 use crate::{db, git, shared_types};
 use tauri::AppHandle;
 
+/// Initializes a git repository in the config directory if one doesn't exist.
+#[tauri::command]
+pub async fn git_init_repo(app: AppHandle) -> Result<shared_types::OkResult, String> {
+    let dir = store::ensure_config_dir_exists(&app).map_err(|e| capture_err("git_init_repo", e))?;
+    git::init_repo(&dir).map_err(|e| capture_err("git_init_repo", e))?;
+    Ok(shared_types::OkResult::yes())
+}
+
+/// Returns original (HEAD) and modified (working-tree) content for each requested file.
+#[tauri::command]
+pub async fn git_file_diff_contents(
+    app: AppHandle,
+    filenames: Vec<String>,
+) -> Result<std::collections::HashMap<String, shared_types::FileDiffContents>, String> {
+    let dir =
+        store::get_config_dir(&app).map_err(|e| capture_err("git_file_diff_contents", e))?;
+    Ok(filenames
+        .into_iter()
+        .map(|f| {
+            let (original, modified) = git::exec::file_diff_contents(&dir, &f);
+            (f, shared_types::FileDiffContents { original, modified })
+        })
+        .collect())
+}
+
 /// Returns the current git status of the config directory.
 #[tauri::command]
 pub async fn git_status(app: AppHandle) -> Result<shared_types::GitStatus, String> {

apps/native/src-tauri/src/commands/ui_prefs.rs

@@ -57,6 +57,10 @@ pub async fn ui_get_prefs(app: AppHandle) -> Result<shared_types::UiPrefs, Strin
         "ui_get_prefs",
         store::get_bool_pref(&app, store::SCAN_HOMEBREW_ON_STARTUP_KEY, true),
     )?;
+    let default_to_diff_tab = wrap_result_and_capture_err(
+        "ui_get_prefs",
+        store::get_bool_pref(&app, store::DEFAULT_TO_DIFF_TAB_KEY, false),
+    )?;
     let developer_mode = wrap_result_and_capture_err(
         "ui_get_prefs",
         store::get_bool_pref(&app, store::DEVELOPER_MODE_KEY, false),
@@ -88,6 +92,7 @@ pub async fn ui_get_prefs(app: AppHandle) -> Result<shared_types::UiPrefs, Strin
         confirm_rollback,
         auto_summarize_on_focus,
         scan_homebrew_on_startup,
+        default_to_diff_tab,
         developer_mode,
         pinned_version,
     })
@@ -173,6 +178,10 @@ pub async fn ui_set_prefs(
         )
         .map_err(|e| capture_err("ui_set_prefs", e))?;
     }
+    if let Some(default_to_diff_tab) = prefs.default_to_diff_tab {
+        store::set_bool_pref(&app, store::DEFAULT_TO_DIFF_TAB_KEY, default_to_diff_tab)
+            .map_err(|e| capture_err("ui_set_prefs", e))?;
+    }
     if let Some(developer_mode) = prefs.developer_mode {
         store::set_bool_pref(&app, store::DEVELOPER_MODE_KEY, developer_mode)
             .map_err(|e| capture_err("ui_set_prefs", e))?;

apps/native/src-tauri/src/editor/lsp.rs

@@ -77,6 +77,9 @@ pub async fn start(app: &AppHandle) -> Result<(), String> {
                 }
             }
         }
+        // Clear state for next open
+        *lsp_state().lock().await = None;
+        let _ = app_handle.emit("lsp:exit", ());
     });
 
     // Spawn stderr reader — log for debugging.

apps/native/src-tauri/src/git/exec.rs

@@ -115,6 +115,29 @@ pub fn get_nix_diff(dir: &str) -> Result<String> {
     Ok(diff)
 }
 
+pub fn repo_root(dir: &str) -> String {
+    git_command()
+        .args(["rev-parse", "--show-toplevel"])
+        .current_dir(dir)
+        .output()
+        .map(|o| String::from_utf8_lossy(&o.stdout).trim().to_string())
+        .unwrap_or_else(|_| dir.to_string())
+}
+
+/// Returns (original, modified) file content for a single file: HEAD content and working-tree content.
+/// Returns empty strings for new files (no HEAD) or deleted files (not on disk).
+pub fn file_diff_contents(dir: &str, filename: &str) -> (String, String) {
+    let original = git_command()
+        .args(["show", &format!("HEAD:{filename}")])
+        .current_dir(dir)
+        .output()
+        .map(|o| String::from_utf8_lossy(&o.stdout).into_owned())
+        .unwrap_or_default();
+    let modified = std::fs::read_to_string(std::path::Path::new(&repo_root(dir)).join(filename))
+        .unwrap_or_default();
+    (original, modified)
+}
+
 /// Returns a diff of tracked changes, optionally restricted to a path glob.
 /// Falls back to staged+unstaged when HEAD is unborn (fresh repo with no commits).
 fn get_tracked_diff(dir: &str, path_filter: Option<&str>) -> Result<String> {

apps/native/src-tauri/src/main.rs

@@ -490,11 +490,13 @@ fn run_gui_mode(
             commands::homebrew::homebrew_apply_diff,
             commands::homebrew::homebrew_get_state_diff,
             // Git
+            commands::git::git_init_repo,
             commands::git::git_status,
             commands::git::git_status_and_cache,
             commands::git::git_cached,
             commands::git::git_commit,
             commands::git::git_stash,
+            commands::git::git_file_diff_contents,
             // Darwin/Nix
             commands::evolve::darwin_evolve,
             commands::evolve::darwin_evolve_cancel,

apps/native/src-tauri/src/shared_types/git.rs

@@ -4,6 +4,14 @@ use specta::Type;
 use super::evolve::EvolveState;
 use crate::sqlite_types::{Change, ChangeSet, ChangeSummary};
 
+/// HEAD content vs working-tree content for a file, used by the diff tab Monaco DiffEditor.
+#[derive(Debug, Clone, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct FileDiffContents {
+    pub original: String,
+    pub modified: String,
+}
+
 /// Type of change for a file in git status.
 #[derive(Debug, Clone, Copy, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]

apps/native/src-tauri/src/shared_types/prefs.rs

@@ -39,6 +39,8 @@ pub struct UiPrefs {
     pub auto_summarize_on_focus: bool,
     /// Whether Homebrew state should be scanned on app startup.
     pub scan_homebrew_on_startup: bool,
+    /// Whether the change view defaults to the Diff tab instead of Summary.
+    pub default_to_diff_tab: bool,
     /// Whether developer-only UI/actions are enabled.
     pub developer_mode: bool,
     /// Version pinned by the user, when update pinning is active.
@@ -84,6 +86,8 @@ pub struct UiPrefsUpdate {
     pub auto_summarize_on_focus: Option<bool>,
     /// Startup Homebrew scan preference update.
     pub scan_homebrew_on_startup: Option<bool>,
+    /// Default-to-diff-tab preference update.
+    pub default_to_diff_tab: Option<bool>,
     /// Developer mode preference update.
     pub developer_mode: Option<bool>,
     /// `None` -> field not sent; `Some(None)` -> clear the pinned version.

apps/native/src-tauri/src/storage/store.rs

@@ -34,6 +34,9 @@ pub const AUTO_SUMMARIZE_ON_FOCUS_KEY: &str = "autoSummarizeOnFocus";
 // Startup scan preference keys
 pub const SCAN_HOMEBREW_ON_STARTUP_KEY: &str = "scanHomebrewOnStartup";
 
+// Default-tab preference keys
+pub const DEFAULT_TO_DIFF_TAB_KEY: &str = "defaultToDiffTab";
+
 // Developer-mode preference keys
 pub const DEVELOPER_MODE_KEY: &str = "developerMode";
 pub const PINNED_VERSION_KEY: &str = "pinnedVersion";

apps/native/src-tauri/src/summarize/sumlog.rs

@@ -9,8 +9,8 @@
 pub const FIND_EXISTING: bool = false;
 pub const GROUP_EXISTING: bool = false;
 pub const SIMPLIFY_GROUP: bool = false;
-pub const FRESH_CHANGESET: bool = false;
-pub const EVOLVED_CHANGESET: bool = false;
+pub const FRESH_CHANGESET: bool = true;
+pub const EVOLVED_CHANGESET: bool = true;
 pub const QUEUE_SUMMARIZER: bool = false;
 
 // ── Imports ───────────────────────────────────────────────────────────────────