fix(ji-do): fix Effect composition bug in ensureSingleCommitForGerrit

Critical bug fix: The squashing logic was not executing due to incorrect
Effect composition.

The Problem:
- ensureSingleCommitForGerrit was using Effect.sync() that returned
  Effect.runSync() for the squashing case
- This caused the inner Effect to never execute
- Result: Multiple commits were pushed to Gerrit without being squashed

The Fix:
- Restructured to use proper Effect.flatMap composition
- First Effect.sync() counts commits and returns the count
- Then Effect.flatMap() conditionally calls squashCommitsForGerrit
- Now the squashing Effect actually executes when needed

Flow:
1. Check if remote is Gerrit (early return if not)
2. Count commits via Effect.sync()
3. Use Effect.flatMap() to conditionally squash if count > 1
4. squashCommitsForGerrit Effect executes properly

This ensures that when ji do creates multiple commits during iterations,
they will be automatically squashed into one before pushing to Gerrit.

Testing:
- All 502 tests pass
- TypeScript compilation succeeds
- Effect composition is now correct

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: aaronshaf

src/cli/commands/do-publish.ts

@@ -108,27 +108,35 @@ const squashCommitsForGerrit = (workingDirectory: string, commitCount: number):
 const ensureSingleCommitForGerrit = (
   workingDirectory: string,
   remoteType: RemoteType,
-): Effect.Effect<void, DoCommandError> =>
-  Effect.sync(() => {
-    if (remoteType !== 'gerrit') {
-      return; // Only enforce for Gerrit
-    }
+): Effect.Effect<void, DoCommandError> => {
+  if (remoteType !== 'gerrit') {
+    return Effect.void; // Only enforce for Gerrit
+  }
 
+  return Effect.sync(() => {
     const commitCount = countCommitsSinceBase(workingDirectory);
 
     if (commitCount === 0) {
       console.log(chalk.yellow('⚠️  No commits found - nothing to publish'));
-      return;
+      return commitCount;
     }
 
     if (commitCount === 1) {
       console.log(chalk.green('✅ Exactly 1 commit found - ready for Gerrit'));
-      return;
+      return commitCount;
     }
 
     // Multiple commits found - need to squash
-    return Effect.runSync(squashCommitsForGerrit(workingDirectory, commitCount));
-  });
+    return commitCount;
+  }).pipe(
+    Effect.flatMap((commitCount) => {
+      if (commitCount > 1) {
+        return squashCommitsForGerrit(workingDirectory, commitCount);
+      }
+      return Effect.void;
+    }),
+  );
+};
 
 /**
  * Executes the configured publish command from .jiconfig.json