fix: propagate ported exceptions instead of flattening them

`ProcessExecutor::execute_args` existed only to turn `execute`'s
`anyhow::Result` into an exit code of 1, so every one of its ~87 call
sites silently took the "command failed" branch on an error PHP would
have thrown. It is gone; callers use `execute` and propagate with `?`.
Where the enclosing function had no `Result` to propagate into, its
signature grew one, up to and including `Git::get_version`,
`Svn::binary_version`, `GitHub`/`GitLab`/`Bitbucket::authorize_oauth`,
`InitCommand::get_git_config` and `DiagnoseCommand::check_git`.

The VCS drivers had the same problem in the other direction: their
`get_contents` returned `Result<Response, Box<TransportException>>`, a
type too narrow for the PHP method, which lets any Throwable out of the
`catch (TransportException $e)` block. Every non-transport error was
therefore rewritten into a `TransportException` with code 0, which the
callers switch on. They now return
`anyhow::Result<Result<Response, Box<TransportException>>>`: the outer
`Result` carries what PHP does not catch, the inner one the exception
the drivers handle.

That signature also restores `GitLabDriver::getContents`: the 400/401
`TransportException`s it raises to force authentication are thrown
inside its own `try` block and handled by its own `catch`, but the port
returned them straight to the caller, so the authentication flow behind
them never ran.

`impl_php_exception!` gains `From<Box<$ty>> for anyhow::Error` so a
caught exception can be re-propagated with `?`.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

1 files changed, 9 insertions, 14 deletions

diff --git a/crates/shirabe/src/util/bitbucket.rs b/crates/shirabe/src/util/bitbucket.rs
index 9a16c9a6..f50dc878 100644
--- a/crates/shirabe/src/util/bitbucket.rs
+++ b/crates/shirabe/src/util/bitbucket.rs
@@ -71,22 +71,17 @@ impl Bitbucket {
         }
     }
 
-    pub fn authorize_oauth(&mut self, origin_url: &str) -> bool {
+    pub fn authorize_oauth(&mut self, origin_url: &str) -> anyhow::Result<bool> {
         if origin_url != "bitbucket.org" {
-            return false;
+            return Ok(false);
         }
 
         let mut output = PhpMixed::Null;
-        if self
-            .process
-            .borrow_mut()
-            .execute(
-                &["git", "config", "bitbucket.accesstoken"],
-                &mut output,
-                None,
-            )
-            .unwrap_or(1)
-            == 0
+        if self.process.borrow_mut().execute(
+            &["git", "config", "bitbucket.accesstoken"],
+            &mut output,
+            None,
+        )? == 0
         {
             let output_str = output.as_string().unwrap_or("").trim().to_string();
             self.io.borrow_mut().set_authentication(
@@ -94,10 +89,10 @@ impl Bitbucket {
                 "x-token-auth".to_string(),
                 Some(output_str),
             );
-            return true;
+            return Ok(true);
         }
 
-        false
+        Ok(false)
     }
 
     fn request_access_token(&mut self) -> anyhow::Result<bool> {