Consistently use context() to preserve sources for anyhow errors (#59112)

When you use `anyhow::anyhow!("{error}")` to convert a preexisting error
to an `anyhow::Error`, the error source can be lost (depending on the
`Display` impl of the error). Anyhow errors can display the whole source
chain when printed. This commit makes us consistently use `context()`
instead to preserve the underlying error's source.

Release Notes:

- N/A

crates/agent/src/db.rs

@@ -2,7 +2,7 @@ use crate::{AgentMessage, AgentMessageContent, UserMessage, UserMessageContent};
 use acp_thread::ClientUserMessageId;
 use agent_client_protocol::schema::v1 as acp;
 use agent_settings::AgentProfileId;
-use anyhow::{Result, anyhow};
+use anyhow::Result;
 use chrono::{DateTime, Utc};
 use collections::{HashMap, IndexMap};
 use futures::{FutureExt, future::Shared};
@@ -444,7 +444,7 @@ impl ThreadsDatabase {
                 data BLOB NOT NULL
             )
         "})?()
-        .map_err(|e| anyhow!("Failed to create threads table: {}", e))?;
+        .map_err(|e| e.context("Failed to create threads table"))?;
 
         if let Ok(mut s) = connection.exec(indoc! {"
             ALTER TABLE threads ADD COLUMN parent_id TEXT

crates/keymap_editor/src/keymap_editor.rs

@@ -3668,7 +3668,7 @@ async fn save_keybinding_update(
         keyboard_mapper,
         deprecated_aliases,
     )
-    .map_err(|err| anyhow::anyhow!("Could not save updated keybinding: {}", err))?;
+    .map_err(|err| err.context("Could not save updated keybinding"))?;
     fs.write(
         paths::keymap_file().as_path(),
         updated_keymap_contents.as_bytes(),

crates/remote/src/transport/ssh.rs

@@ -496,7 +496,9 @@ impl RemoteConnection for SshRemoteConnection {
         {
             Ok(process) => process,
             Err(error) => {
-                return Task::ready(Err(anyhow!("failed to spawn remote server: {}", error)));
+                return Task::ready(Err(
+                    anyhow::Error::new(error).context("failed to spawn remote server")
+                ));
             }
         };
 

crates/remote/src/transport/wsl.rs

@@ -210,7 +210,7 @@ impl WslRemoteConnection {
             let mkdir = self.shell_kind.prepend_command_prefix("mkdir");
             self.run_wsl_command(&mkdir, &["-p", &parent])
                 .await
-                .map_err(|e| anyhow!("Failed to create directory: {}", e))?;
+                .map_err(|e| e.context("Failed to create directory"))?;
         }
 
         let binary_exists_on_server = self
@@ -346,7 +346,7 @@ impl WslRemoteConnection {
 
         self.run_wsl_command("sh", &["-c", &script])
             .await
-            .map_err(|e| anyhow!("Failed to extract server binary: {}", e))?;
+            .map_err(|e| e.context("Failed to extract server binary"))?;
         Ok(())
     }
 }
@@ -395,7 +395,9 @@ impl RemoteConnection for WslRemoteConnection {
             {
                 Ok(process) => process,
                 Err(error) => {
-                    return Task::ready(Err(anyhow!("failed to spawn remote server: {}", error)));
+                    return Task::ready(Err(
+                        anyhow::Error::new(error).context("failed to spawn remote server")
+                    ));
                 }
             };