refactor: remove deterministic caching system from skills engine (#453)

skills-engine/merge.ts

@@ -1,6 +1,4 @@
 import { execFileSync, execSync } from 'child_process';
-import fs from 'fs';
-import path from 'path';
 
 import { MergeResult } from './types.js';
 
@@ -39,112 +37,3 @@ export function mergeFile(
     throw new Error(`git merge-file failed: ${err.message}`);
   }
 }
-
-/**
- * Set up unmerged index entries for rerere adapter.
- * Creates stages 1/2/3 so git rerere can record/resolve conflicts.
- */
-export function setupRerereAdapter(
-  filePath: string,
-  baseContent: string,
-  oursContent: string,
-  theirsContent: string,
-): void {
-  if (!isGitRepo()) return;
-
-  const gitDir = execSync('git rev-parse --git-dir', {
-    encoding: 'utf-8',
-  }).trim();
-
-  // Clean up stale MERGE_HEAD from a previous crash
-  if (fs.existsSync(path.join(gitDir, 'MERGE_HEAD'))) {
-    cleanupMergeState(filePath);
-  }
-
-  // Hash objects into git object store
-  const baseHash = execSync('git hash-object -w --stdin', {
-    input: baseContent,
-    encoding: 'utf-8',
-  }).trim();
-  const oursHash = execSync('git hash-object -w --stdin', {
-    input: oursContent,
-    encoding: 'utf-8',
-  }).trim();
-  const theirsHash = execSync('git hash-object -w --stdin', {
-    input: theirsContent,
-    encoding: 'utf-8',
-  }).trim();
-
-  // Create unmerged index entries (stages 1/2/3)
-  const indexInfo = [
-    `100644 ${baseHash} 1\t${filePath}`,
-    `100644 ${oursHash} 2\t${filePath}`,
-    `100644 ${theirsHash} 3\t${filePath}`,
-  ].join('\n');
-
-  execSync('git update-index --index-info', {
-    input: indexInfo,
-    stdio: ['pipe', 'pipe', 'pipe'],
-  });
-
-  // Set MERGE_HEAD and MERGE_MSG (required for rerere)
-  const headHash = execSync('git rev-parse HEAD', {
-    encoding: 'utf-8',
-  }).trim();
-  fs.writeFileSync(path.join(gitDir, 'MERGE_HEAD'), headHash + '\n');
-  fs.writeFileSync(
-    path.join(gitDir, 'MERGE_MSG'),
-    `Skill merge: ${filePath}\n`,
-  );
-}
-
-/**
- * Run git rerere to record or auto-resolve conflicts.
- * When filePath is given, checks that specific file for remaining conflict markers.
- * Returns true if rerere auto-resolved the conflict.
- */
-export function runRerere(filePath: string): boolean {
-  if (!isGitRepo()) return false;
-
-  try {
-    execSync('git rerere', { stdio: 'pipe' });
-
-    // Check if the specific working tree file still has conflict markers.
-    // rerere resolves the working tree but does NOT update the index,
-    // so checking unmerged index entries would give a false negative.
-    const content = fs.readFileSync(filePath, 'utf-8');
-    return !content.includes('<<<<<<<');
-  } catch {
-    return false;
-  }
-}
-
-/**
- * Clean up merge state after rerere operations.
- * Pass filePath to only reset that file's index entries (preserving user's staged changes).
- */
-export function cleanupMergeState(filePath?: string): void {
-  if (!isGitRepo()) return;
-
-  const gitDir = execSync('git rev-parse --git-dir', {
-    encoding: 'utf-8',
-  }).trim();
-
-  // Remove merge markers
-  const mergeHead = path.join(gitDir, 'MERGE_HEAD');
-  const mergeMsg = path.join(gitDir, 'MERGE_MSG');
-  if (fs.existsSync(mergeHead)) fs.unlinkSync(mergeHead);
-  if (fs.existsSync(mergeMsg)) fs.unlinkSync(mergeMsg);
-
-  // Reset only the specific file's unmerged index entries to avoid
-  // dropping the user's pre-existing staged changes
-  try {
-    if (filePath) {
-      execFileSync('git', ['reset', '--', filePath], { stdio: 'pipe' });
-    } else {
-      execSync('git reset', { stdio: 'pipe' });
-    }
-  } catch {
-    // May fail if nothing staged
-  }
-}