Use --rebase instead of --no-edit in gitPull

git pull --no-edit fails with exit 128 on divergent branches because
fast-forward is impossible.  Using --rebase handles divergent histories
by rebasing local commits on top of fetched remote commits, producing
a linear history without merge commits.

- src/Converge.hs: Change gitPull from --no-edit to --rebase
- test/GitPullSpec.hs: Update rebase test to expect success and
  verify linear history (3 commits, no merge parents)
- test/*.hs: Clean up unused imports

src/Converge.hs

@@ -305,7 +305,7 @@ gitPull :: RepoConfig -> IO (ExitCode, Text, Text)
 gitPull repo =
     runGitIn
         (rcPath repo)
-        ["pull", "--no-edit", T.unpack (rcRemote repo), T.unpack (rcBranch repo)]
+        ["pull", "--rebase", T.unpack (rcRemote repo), T.unpack (rcBranch repo)]
 
 -- | Check if the repository currently has merge conflicts.
 hasConflicts :: FilePath -> IO Bool

test/GitCommitSpec.hs

@@ -1,11 +1,9 @@
 module GitCommitSpec (spec) where
 
 import Converge (gitCommitAll)
-import Data.Text (Text)
 import qualified Data.Text as T
 import System.Exit (ExitCode (..))
 import System.FilePath ((</>))
-import System.IO (writeFile)
 import Test.Hspec
 import TestHelper
 

test/GitPullSpec.hs

@@ -5,7 +5,6 @@ import qualified Data.Text as T
 import System.Directory (createDirectory)
 import System.Exit (ExitCode (..))
 import System.FilePath ((</>))
-import System.IO (writeFile)
 import System.IO.Temp (withSystemTempDirectory)
 import Test.Hspec
 import TestHelper
@@ -72,13 +71,15 @@ spec = do
                 _ <- runGitIn otherDir ["commit", "-m", "remote commit"]
                 _ <- runGitIn otherDir ["push", "origin", "main"]
 
-                -- Pull into local with divergent history.
-                -- CURRENT BEHAVIOR: git pull --no-edit fails on divergent
-                -- branches (exit 128).  The spec requires rebase instead.
-                -- When --rebase is implemented, expect ExitSuccess and
-                -- linear history (commit count = 3).
+                -- Pull with --rebase: local commits are rebased on top
+                -- of the fetched remote commit, yielding a linear history.
                 let cfg = defaultRepoConfig {rcPath = localDir}
-                (code, _, err) <- gitPull cfg
-                -- Document current gap: divergent pull fails
-                code `shouldSatisfy` (/= ExitSuccess)
-                err `shouldSatisfy` ("fast-forward" `T.isInfixOf`)
+                (code, _, _) <- gitPull cfg
+                code `shouldBe` ExitSuccess
+                -- Rebase produces linear history: 3 commits, no merge commit
+                c <- commitCount localDir
+                c `shouldBe` 3
+                -- Verify no merge commits exist (each commit has exactly 1 parent)
+                (_, logOut, _) <- runGitIn localDir ["log", "--format=%P", "--all"]
+                let parentCounts = map (length . words) (lines (T.unpack logOut))
+                parentCounts `shouldSatisfy` all (<= 1)

test/TestHelper.hs

@@ -22,7 +22,6 @@ import qualified Data.Text as T
 import System.Directory (createDirectory)
 import System.Exit (ExitCode)
 import System.FilePath ((</>))
-import System.IO (writeFile)
 import System.IO.Temp (withSystemTempDirectory)
 import System.Process (readProcessWithExitCode)