Log all git write operations with command, args, and exit code

- Add loggedGit helper that logs 'RUN: git -C <path> <args>' before
  execution and 'EXIT <code>' after (with stderr on failure)
- Refactor gitCommitAll, gitPull, and gitPush to use loggedGit
- Add Logger parameter to gitPull and gitPush
- Update test call sites and syncRepo to pass Logger

test/GitPullSpec.hs

@@ -13,6 +13,7 @@ spec :: Spec
 spec = do
     describe "gitPull" $ do
         it "pulls changes from remote 'origin'" $ do
+            logger <- testLogger
             withTempGitRepoWithRemote $ \local -> do
                 -- Make a second commit on local and push to remote
                 writeFile (local </> "upstream.txt") "pushed to remote"
@@ -27,13 +28,14 @@ spec = do
                 countBefore `shouldBe` 1
 
                 let cfg = defaultRepoConfig{rcPath = local}
-                (code, _, _) <- gitPull cfg
+                (code, _, _) <- gitPull logger cfg
                 code `shouldBe` ExitSuccess
 
                 countAfter <- commitCount local
                 countAfter `shouldBe` 2
 
         it "rebases local commits on top of pulled changes" $ do
+            logger <- testLogger
             withSystemTempDirectory "converge-test-rebase" $ \tmp -> do
                 let remoteDir = tmp </> "remote.git"
                 let localDir = tmp </> "local"
@@ -73,7 +75,7 @@ spec = do
                 -- Pull with --rebase: local commits are rebased on top
                 -- of the fetched remote commit, yielding a linear history.
                 let cfg = defaultRepoConfig{rcPath = localDir}
-                (code, _, _) <- gitPull cfg
+                (code, _, _) <- gitPull logger cfg
                 code `shouldBe` ExitSuccess
                 -- Rebase produces linear history: 3 commits, no merge commit
                 c <- commitCount localDir