feat(windows): add shell detection and fix cmd.exe escaping issues

WINDOWS.md

@@ -79,34 +79,50 @@ Codebuff checks GitHub for the latest release on first run. This fails when:
 
 ---
 
+### Shell Detection & PowerShell Support
+
+Codebuff now automatically detects your shell (PowerShell, cmd.exe, bash, etc.) and adapts its behavior accordingly.
+
+**PowerShell users benefit from:**
+- Many Unix-like commands work natively (`mkdir`, `rm`, `cp`, `mv`, `ls`, `cat`)
+- Better compatibility with cross-platform commands
+- Codebuff generates shell-appropriate commands based on detection
+
+**To check your detected shell:**
+Look at the "Shell:" line in the system info at the start of each conversation.
+
+**Recommendation:** Use PowerShell instead of cmd.exe for the best Windows experience.
+
+---
+
 ### Issue: Git Commands Fail on Windows
 
 **Symptom**:
 Git operations (commit, rebase, complex commands) fail with syntax errors or unexpected behavior.
 
-**Cause**:
-Codebuff uses Windows `cmd.exe` for command execution, which:
-- Does not support bash syntax (HEREDOC, process substitution)
-- Has limited quote escaping compared to bash
-- Cannot execute complex git commands that work in Git Bash
+**Cause** (now largely fixed):
+Older versions of Codebuff used HEREDOC syntax for git commits, which doesn't work on Windows. This has been fixed - Codebuff now uses cross-platform compatible syntax.
 
-**Solutions**:
+**If you still experience issues:**
+
+1. **Ensure you have the latest Codebuff version**:
+   ```powershell
+   npm update -g codebuff
+   ```
 
-1. **Install Git for Windows** (if not already installed):
+2. **Install Git for Windows** (if not already installed):
    - Download from https://git-scm.com/download/win
    - Ensures git commands are available in PATH
 
-2. **Use Git Bash terminal** instead of PowerShell:
-   - Git Bash provides better compatibility with bash-style commands
-   - Launch Git Bash and run `codebuff` from there
+3. **Use PowerShell** instead of cmd.exe:
+   - PowerShell has better command compatibility
+   - Codebuff detects PowerShell and adjusts accordingly
 
-3. **Or use WSL (Windows Subsystem for Linux)**:
+4. **Or use WSL (Windows Subsystem for Linux)**:
    - Provides full Linux environment with native bash
    - Install: `wsl --install` in PowerShell (Admin)
    - Run codebuff inside WSL for best compatibility
 
-**Note**: Even when running in Git Bash, Codebuff spawns commands using `cmd.exe`. Using WSL provides the most reliable experience for git operations.
-
 **Reference**: Issue [#274](https://github.com/CodebuffAI/codebuff/issues/274)
 
 ---

cli/src/utils/detect-shell.ts

@@ -1,115 +1,32 @@
-import { execSync } from 'child_process'
+/**
+ * CLI-specific shell detection wrapper.
+ * Re-exports from common/src/util/detect-shell.ts with CLI environment integration.
+ */
+import {
+  detectShell as detectShellFromCommon,
+  clearShellCache,
+  getShellArgs,
+  SHELL_COMMAND_ARGS,
+} from '@codebuff/common/util/detect-shell'
 
 import type { CliEnv } from '../types/env'
 import { getCliEnv } from './env'
 
-type KnownShell =
-  | 'bash'
-  | 'zsh'
-  | 'fish'
-  | 'cmd.exe'
-  | 'powershell'
-  | 'unknown'
-
-type ShellName = KnownShell | string
-
-let cachedShell: ShellName | null = null
-
-const SHELL_ALIASES: Record<string, KnownShell> = {
-  bash: 'bash',
-  zsh: 'zsh',
-  fish: 'fish',
-  cmd: 'cmd.exe',
-  'cmd.exe': 'cmd.exe',
-  pwsh: 'powershell',
-  powershell: 'powershell',
-  'powershell.exe': 'powershell',
-}
-
+import type {
+  KnownShell,
+  ShellName,
+  ShellDetectionEnv,
+} from '@codebuff/common/util/detect-shell'
+
+// Re-export types and utilities from common
+export type { KnownShell, ShellName, ShellDetectionEnv }
+export { clearShellCache, getShellArgs, SHELL_COMMAND_ARGS }
+
+/**
+ * Detects the user's shell using CLI environment variables.
+ * This is a convenience wrapper around the common detectShell function
+ * that automatically uses the CLI environment.
+ */
 export function detectShell(env: CliEnv = getCliEnv()): ShellName {
-  if (cachedShell) {
-    return cachedShell
-  }
-
-  const detected =
-    detectFromEnvironment(env) ?? detectViaParentProcessInspection() ?? 'unknown'
-  cachedShell = detected
-  return detected
-}
-
-function detectFromEnvironment(env: CliEnv): ShellName | null {
-  const candidates: Array<string | undefined> = []
-
-  if (process.platform === 'win32') {
-    candidates.push(env.COMSPEC, env.SHELL)
-  } else {
-    candidates.push(env.SHELL)
-  }
-
-  for (const candidate of candidates) {
-    const normalized = normalizeCandidate(candidate)
-    if (normalized) {
-      return normalized
-    }
-  }
-
-  return null
-}
-
-function detectViaParentProcessInspection(): ShellName | null {
-  try {
-    if (process.platform === 'win32') {
-      const parentProcess = execSync(
-        'wmic process get ParentProcessId,CommandLine',
-        { stdio: 'pipe' },
-      )
-        .toString()
-        .toLowerCase()
-
-      if (parentProcess.includes('powershell')) return 'powershell'
-      if (parentProcess.includes('cmd.exe')) return 'cmd.exe'
-    } else {
-      const parentProcess = execSync(`ps -p ${process.ppid} -o comm=`, {
-        stdio: 'pipe',
-      })
-        .toString()
-        .trim()
-      const normalized = normalizeCandidate(parentProcess)
-      if (normalized) return normalized
-    }
-  } catch {
-    // Ignore inspection errors
-  }
-
-  return null
-}
-
-function normalizeCandidate(value?: string | null): ShellName | null {
-  if (!value) {
-    return null
-  }
-
-  const trimmed = value.trim()
-  if (!trimmed) {
-    return null
-  }
-
-  const lower = trimmed.toLowerCase()
-  const parts = lower.split(/[/\\]/)
-  const last = parts.pop() ?? lower
-  const base = last.endsWith('.exe') ? last.slice(0, -4) : last
-
-  if (SHELL_ALIASES[base]) {
-    return SHELL_ALIASES[base]
-  }
-
-  if (SHELL_ALIASES[last]) {
-    return SHELL_ALIASES[last]
-  }
-
-  if (base.endsWith('sh')) {
-    return base
-  }
-
-  return null
+  return detectShellFromCommon(env)
 }

common/src/tools/params/tool/run-terminal-command.ts

@@ -62,28 +62,23 @@ When the user requests a new git commit, please follow these steps closely:
    Generated with Codebuff 🤖
    Co-Authored-By: Codebuff <noreply@codebuff.com>
    \`\`\`
-   To maintain proper formatting, use cross-platform compatible commit messages:
 
-   **For Unix/bash shells:**
-   \`\`\`
-   git commit -m "$(cat <<'EOF'
-   Your commit message here.
-
-   🤖 Generated with Codebuff
-   Co-Authored-By: Codebuff <noreply@codebuff.com>
-   EOF
-   )"
-   \`\`\`
-
-   **For Windows Command Prompt:**
+   **For bash/PowerShell:** Use multi-line \`-m\` format:
    \`\`\`
    git commit -m "Your commit message here.
 
    🤖 Generated with Codebuff
    Co-Authored-By: Codebuff <noreply@codebuff.com>"
    \`\`\`
 
-   Always detect the platform and use the appropriate syntax. HEREDOC syntax (\`<<'EOF'\`) only works in bash/Unix shells and will fail on Windows Command Prompt.
+   **For cmd.exe (Windows Command Prompt):** Use the file-based approach to avoid escaping issues:
+   1. Use \`write_file\` to create \`.codebuff-commit-msg.txt\` with the full commit message
+   2. Run \`git commit -F .codebuff-commit-msg.txt\`
+   3. Run \`del .codebuff-commit-msg.txt\` to clean up
+
+   This file-based approach completely avoids cmd.exe's complex escaping rules for quotes, newlines, and special characters.
+
+   **Important:** Do NOT use HEREDOC syntax (\`<<'EOF'\`) - it only works in bash and will fail on Windows.
 
 **Important details**