fix(git): surface non-git-repo as a typed error and align all panels via workspace state

Consolidate `.git` presence detection into a shared `git_repo` module used by both the workspace state watcher and the command preflight helper, replacing duplicated local definitions.

Introduce `AppErrorCode::NotAGitRepository` (HTTP 422) and preflight eleven frontend-callable git commands (log, status, list-branches, diff, diff-with-branch, show-diff, show-file, push-info, list-remotes, list-all-branches, commit-branches) so non-git folders short-circuit with a structured error instead of leaking locale-dependent git stderr.

Frontend `isNotAGitRepoError` checks the error code first and falls back to a multi-language regex list centralized in `src/i18n/git-error-patterns.ts`, covering the nine languages git actually translates into.

Wire the git log panel to `workspaceState.isGitRepo` rather than a local cached flag, so running `git init` or deleting `.git` externally propagates through the watcher and refreshes the panel automatically.

src-tauri/src/app_error.rs

@@ -9,6 +9,7 @@ pub enum AppErrorCode {
     ConfigurationMissing,
     ConfigurationInvalid,
     NotFound,
+    NotAGitRepository,
     AlreadyExists,
     PermissionDenied,
     DependencyMissing,
@@ -65,6 +66,10 @@ impl AppCommandError {
         Self::new(AppErrorCode::NotFound, message)
     }
 
+    pub fn not_a_git_repository(message: impl Into<String>) -> Self {
+        Self::new(AppErrorCode::NotAGitRepository, message)
+    }
+
     pub fn already_exists(message: impl Into<String>) -> Self {
         Self::new(AppErrorCode::AlreadyExists, message)
     }

src-tauri/src/commands/folders.rs

@@ -307,6 +307,8 @@ fn git_command_error(operation: &str, stderr: &[u8]) -> AppCommandError {
     AppCommandError::external_command(format!("git {operation} failed"), stderr)
 }
 
+use crate::git_repo::ensure_git_repo;
+
 async fn detect_conflicts(path: &str) -> Result<Vec<String>, AppCommandError> {
     let output = crate::process::tokio_command("git")
         .args(["-c", "core.quotePath=false"])
@@ -902,6 +904,8 @@ pub async fn git_fetch(
 
 #[cfg_attr(feature = "tauri-runtime", tauri::command)]
 pub async fn git_push_info(path: String) -> Result<GitPushInfo, AppCommandError> {
+    ensure_git_repo(&path)?;
+
     // Get current branch name
     let branch_output = crate::process::tokio_command("git")
         .args(["rev-parse", "--abbrev-ref", "HEAD"])
@@ -1186,6 +1190,8 @@ pub async fn git_reset(
 
 #[cfg_attr(feature = "tauri-runtime", tauri::command)]
 pub async fn git_list_branches(path: String) -> Result<Vec<String>, AppCommandError> {
+    ensure_git_repo(&path)?;
+
     let output = crate::process::tokio_command("git")
         .args(["branch", "--format=%(refname:short)"])
         .current_dir(&path)
@@ -1401,6 +1407,8 @@ pub async fn git_status(
     path: String,
     show_all_untracked: Option<bool>,
 ) -> Result<Vec<GitStatusEntry>, AppCommandError> {
+    ensure_git_repo(&path)?;
+
     let untracked_mode = if show_all_untracked.unwrap_or(false) {
         "-uall"
     } else {
@@ -1446,6 +1454,8 @@ pub async fn git_is_tracked(path: String, file: String) -> Result<bool, AppComma
 
 #[cfg_attr(feature = "tauri-runtime", tauri::command)]
 pub async fn git_diff(path: String, file: Option<String>) -> Result<String, AppCommandError> {
+    ensure_git_repo(&path)?;
+
     let literal_file = file.as_deref().map(to_git_literal_pathspec);
     let mut args = vec!["diff".to_string(), "HEAD".to_string()];
     if let Some(ref f) = literal_file {
@@ -1485,6 +1495,8 @@ pub async fn git_diff_with_branch(
     branch: String,
     file: Option<String>,
 ) -> Result<String, AppCommandError> {
+    ensure_git_repo(&path)?;
+
     let target_branch = branch.trim();
     if target_branch.is_empty() {
         return Err(AppCommandError::invalid_input(
@@ -1527,6 +1539,8 @@ pub async fn git_show_diff(
     commit: String,
     file: Option<String>,
 ) -> Result<String, AppCommandError> {
+    ensure_git_repo(&path)?;
+
     let literal_file = file.as_deref().map(to_git_literal_pathspec);
     let mut args = vec![
         "show".to_string(),
@@ -1559,6 +1573,8 @@ pub async fn git_show_file(
     file: String,
     ref_name: Option<String>,
 ) -> Result<String, AppCommandError> {
+    ensure_git_repo(&path)?;
+
     let git_ref = ref_name.unwrap_or_else(|| "HEAD".to_string());
     let file_spec = format!("{}:{}", git_ref, file);
 
@@ -1783,6 +1799,8 @@ pub async fn git_add_files(path: String, files: Vec<String>) -> Result<(), AppCo
 
 #[cfg_attr(feature = "tauri-runtime", tauri::command)]
 pub async fn git_list_all_branches(path: String) -> Result<GitBranchList, AppCommandError> {
+    ensure_git_repo(&path)?;
+
     let local_fut = crate::process::tokio_command("git")
         .args(["branch", "--format=%(refname:short)"])
         .current_dir(&path)
@@ -1857,6 +1875,8 @@ pub async fn git_list_all_branches(path: String) -> Result<GitBranchList, AppCom
 
 #[cfg_attr(feature = "tauri-runtime", tauri::command)]
 pub async fn git_list_remotes(path: String) -> Result<Vec<GitRemote>, AppCommandError> {
+    ensure_git_repo(&path)?;
+
     let output = crate::process::tokio_command("git")
         .args(["remote", "-v"])
         .current_dir(&path)
@@ -3201,6 +3221,8 @@ pub async fn git_log(
     branch: Option<String>,
     remote: Option<String>,
 ) -> Result<GitLogResult, AppCommandError> {
+    ensure_git_repo(&path)?;
+
     const COMMIT_META_PREFIX: &str = "__COMMIT__\0";
     const MESSAGE_END_MARKER: &str = "__COMMIT_MESSAGE_END__";
 
@@ -3317,6 +3339,8 @@ pub async fn git_commit_branches(
     path: String,
     commit: String,
 ) -> Result<Vec<String>, AppCommandError> {
+    ensure_git_repo(&path)?;
+
     let contains_arg = format!("--contains={commit}");
     let output = crate::process::tokio_command("git")
         .args([

src-tauri/src/git_repo.rs

@@ -0,0 +1,40 @@
+//! Single source of truth for "is this path a git repository?" detection.
+//!
+//! The check is deliberately strict: the exact path must contain a `.git`
+//! entry (directory for regular repos, file for linked worktrees and
+//! submodules). We do **not** walk up to ancestors.
+//!
+//! Rationale: codeg scopes every workspace-facing feature (file tree
+//! watcher, git changes panel, log panel) to the directory the user opens.
+//! If one code path walks up and another doesn't, the UI falls into a
+//! "schizophrenic" state where some panels see a repo and others don't.
+//! Keeping the primitive strict forces every consumer onto the same
+//! interpretation.
+//!
+//! Bare repositories are intentionally not supported — they have no working
+//! tree, which makes them an unusual target for a workspace-oriented editor.
+
+use std::path::Path;
+
+use crate::app_error::AppCommandError;
+
+/// Returns true when `path` is the root of a git working tree.
+///
+/// `.git` may be a directory (normal repo) or a file (worktree/submodule
+/// pointer). `Path::exists` treats both as present.
+pub fn is_git_repo(path: &Path) -> bool {
+    path.join(".git").exists()
+}
+
+/// Preflight guard for git commands. Short-circuits with a typed error code
+/// when the target path is not a git working tree, so callers avoid locale-
+/// dependent stderr parsing for the most common "wrong folder" failure.
+pub fn ensure_git_repo(path: &str) -> Result<(), AppCommandError> {
+    if is_git_repo(Path::new(path)) {
+        Ok(())
+    } else {
+        Err(AppCommandError::not_a_git_repository(format!(
+            "Not a Git repository: {path}"
+        )))
+    }
+}

src-tauri/src/lib.rs

@@ -5,6 +5,7 @@ pub mod chat_channel;
 pub mod commands;
 pub mod db;
 pub mod git_credential;
+pub mod git_repo;
 pub mod keyring_store;
 mod models;
 mod network;

src-tauri/src/web/handlers/error.rs

@@ -16,7 +16,8 @@ impl IntoResponse for AppCommandError {
             AppErrorCode::AuthenticationFailed => StatusCode::UNAUTHORIZED,
             AppErrorCode::ConfigurationMissing
             | AppErrorCode::ConfigurationInvalid
-            | AppErrorCode::DependencyMissing => StatusCode::UNPROCESSABLE_ENTITY,
+            | AppErrorCode::DependencyMissing
+            | AppErrorCode::NotAGitRepository => StatusCode::UNPROCESSABLE_ENTITY,
             AppErrorCode::NetworkError
             | AppErrorCode::DatabaseError
             | AppErrorCode::IoError

src-tauri/src/workspace_state/mod.rs

@@ -13,6 +13,7 @@ use tokio::sync::mpsc::error::TrySendError;
 
 use crate::app_error::AppCommandError;
 use crate::commands::folders::{self, FileTreeNode};
+use crate::git_repo::is_git_repo;
 use crate::web::event_bridge::{emit_event, EventEmitter};
 
 pub const WORKSPACE_STATE_PROTOCOL_VERSION: u16 = 1;
@@ -580,10 +581,6 @@ async fn git_numstat_map(path: &str) -> HashMap<String, (i32, i32)> {
         .unwrap_or_default()
 }
 
-fn is_git_repo(root: &Path) -> bool {
-    root.join(".git").exists()
-}
-
 async fn collect_git_snapshot(path: &str) -> Result<Vec<WorkspaceGitEntry>, AppCommandError> {
     let status_entries = folders::git_status(path.to_string(), Some(true)).await?;