fix: address PR #173 security and code quality feedback

Security fixes:
- Enhanced branch name sanitization for cross-platform filesystem safety
  (handles Windows-invalid chars, reserved names, path length limits)
- Added branch name validation in pr-info.ts to prevent command injection
- Sanitized prUrl in kanban-card to only allow http/https URLs

Code quality improvements:
- Fixed placeholder issue where {owner}/{repo} was passed literally to gh api
- Replaced async forEach with Promise.all for proper async handling
- Display PR number extracted from URL in kanban cards

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/server/src/routes/worktree/routes/create-pr.ts

@@ -8,6 +8,24 @@ import { promisify } from "util";
 import { getErrorMessage, logError } from "../common.js";
 import { updateWorktreePRInfo } from "../../../lib/worktree-metadata.js";
 
+// Shell escaping utility to prevent command injection
+function shellEscape(arg: string): string {
+  if (process.platform === "win32") {
+    // Windows CMD shell escaping
+    return `"${arg.replace(/"/g, '""')}"`;
+  } else {
+    // Unix shell escaping
+    return `'${arg.replace(/'/g, "'\\''")}'`;
+  }
+}
+
+// Validate branch name to prevent command injection
+function isValidBranchName(name: string): boolean {
+  // Git branch names cannot contain: space, ~, ^, :, ?, *, [, \, or control chars
+  // Also reject shell metacharacters for safety
+  return /^[a-zA-Z0-9._\-/]+$/.test(name) && name.length < 250;
+}
+
 const execAsync = promisify(exec);
 
 // Extended PATH to include common tool installation locations
@@ -78,6 +96,15 @@ export function createCreatePRHandler() {
       );
       const branchName = branchOutput.trim();
 
+      // Validate branch name for security
+      if (!isValidBranchName(branchName)) {
+        res.status(400).json({
+          success: false,
+          error: "Invalid branch name contains unsafe characters",
+        });
+        return;
+      }
+
       // Check for uncommitted changes
       const { stdout: status } = await execAsync("git status --porcelain", {
         cwd: worktreePath,

apps/server/src/routes/worktree/routes/pr-info.ts

@@ -42,6 +42,15 @@ const execEnv = {
   PATH: extendedPath,
 };
 
+/**
+ * Validate branch name to prevent command injection.
+ * Git branch names cannot contain: space, ~, ^, :, ?, *, [, \, or control chars.
+ * We also reject shell metacharacters for safety.
+ */
+function isValidBranchName(name: string): boolean {
+  return /^[a-zA-Z0-9._\-/]+$/.test(name) && name.length < 250;
+}
+
 export interface PRComment {
   id: number;
   author: string;
@@ -79,6 +88,15 @@ export function createPRInfoHandler() {
         return;
       }
 
+      // Validate branch name to prevent command injection
+      if (!isValidBranchName(branchName)) {
+        res.status(400).json({
+          success: false,
+          error: "Invalid branch name contains unsafe characters",
+        });
+        return;
+      }
+
       // Check if gh CLI is available
       let ghCliAvailable = false;
       try {
@@ -226,35 +244,38 @@ export function createPRInfoHandler() {
 
         // Get review comments (inline code comments)
         let reviewComments: PRComment[] = [];
-        try {
-          const reviewsEndpoint = targetRepo
-            ? `repos/${targetRepo}/pulls/${prNumber}/comments`
-            : `repos/{owner}/{repo}/pulls/${prNumber}/comments`;
-          const reviewsCmd = `gh api ${reviewsEndpoint}`;
-          const { stdout: reviewsOutput } = await execAsync(
-            reviewsCmd,
-            { cwd: worktreePath, env: execEnv }
-          );
-          const reviewsData = JSON.parse(reviewsOutput);
-          reviewComments = reviewsData.map((c: {
-            id: number;
-            user: { login: string };
-            body: string;
-            path: string;
-            line?: number;
-            original_line?: number;
-            created_at: string;
-          }) => ({
-            id: c.id,
-            author: c.user?.login || "unknown",
-            body: c.body,
-            path: c.path,
-            line: c.line || c.original_line,
-            createdAt: c.created_at,
-            isReviewComment: true,
-          }));
-        } catch (error) {
-          console.warn("[PRInfo] Failed to fetch review comments:", error);
+        // Only fetch review comments if we have repository info
+        if (targetRepo) {
+          try {
+            const reviewsEndpoint = `repos/${targetRepo}/pulls/${prNumber}/comments`;
+            const reviewsCmd = `gh api ${reviewsEndpoint}`;
+            const { stdout: reviewsOutput } = await execAsync(
+              reviewsCmd,
+              { cwd: worktreePath, env: execEnv }
+            );
+            const reviewsData = JSON.parse(reviewsOutput);
+            reviewComments = reviewsData.map((c: {
+              id: number;
+              user: { login: string };
+              body: string;
+              path: string;
+              line?: number;
+              original_line?: number;
+              created_at: string;
+            }) => ({
+              id: c.id,
+              author: c.user?.login || "unknown",
+              body: c.body,
+              path: c.path,
+              line: c.line || c.original_line,
+              createdAt: c.created_at,
+              isReviewComment: true,
+            }));
+          } catch (error) {
+            console.warn("[PRInfo] Failed to fetch review comments:", error);
+          }
+        } else {
+          console.warn("[PRInfo] Cannot fetch review comments: repository info not available");
         }
 
         const prInfo: PRInfo = {