Implement profile management (task 14)

- Add updateProfile and updatePassword server actions
- Add getUserProfile function with sensitive data protection
- Create ProfileForm component for name and email updates
- Create PasswordChangeForm component with current password verification
- Create profile page at /profile with all profile management features
- Add profile and invitations navigation links to main page
- Implement email uniqueness validation
- Implement password hashing on password change

Requirements: 7.1, 7.2, 7.3, 7.4, 7.5

lib/auth-actions.ts

@@ -173,3 +173,157 @@ export async function isAuthenticated(): Promise<boolean> {
   const session = await getCurrentSession()
   return !!session?.user
 }
+
+// Profile management schemas
+const updateProfileSchema = z.object({
+  name: z.string().min(1, { message: 'Name is required' }).max(100, { message: 'Name must be less than 100 characters' }).optional(),
+  email: z.string().email({ message: 'Invalid email address' }).optional(),
+})
+
+const updatePasswordSchema = z.object({
+  currentPassword: z.string().min(1, { message: 'Current password is required' }),
+  newPassword: z.string().min(8, { message: 'New password must be at least 8 characters' }),
+})
+
+export type UpdateProfileResult = 
+  | { success: true }
+  | { success: false; error: string }
+
+export type UpdatePasswordResult = 
+  | { success: true }
+  | { success: false; error: string }
+
+/**
+ * Update user profile information
+ * Requirements: 7.1, 7.4, 7.5
+ */
+export async function updateProfile(
+  userId: string,
+  data: { name?: string; email?: string }
+): Promise<UpdateProfileResult> {
+  try {
+    // Validate input
+    const validation = updateProfileSchema.safeParse(data)
+    
+    if (!validation.success) {
+      const errors = validation.error.issues.map((issue) => issue.message).join(', ')
+      return { success: false, error: errors }
+    }
+
+    const { name, email } = validation.data
+
+    // Check if there's anything to update
+    if (!name && !email) {
+      return { success: false, error: 'No data to update' }
+    }
+
+    // If email is being updated, check uniqueness (Requirement 7.4)
+    if (email) {
+      const existingUser = await prisma.user.findUnique({
+        where: { email },
+      })
+
+      // Check if email is already in use by another user
+      if (existingUser && existingUser.id !== userId) {
+        return { success: false, error: 'Email already in use' }
+      }
+    }
+
+    // Update user profile (Requirement 7.1)
+    await prisma.user.update({
+      where: { id: userId },
+      data: {
+        ...(name !== undefined && { name }),
+        ...(email !== undefined && { email }),
+      },
+    })
+
+    return { success: true }
+  } catch (error) {
+    console.error('Profile update error:', error)
+    
+    // Handle unique constraint violation
+    if (error instanceof Error && error.message.includes('Unique constraint')) {
+      return { success: false, error: 'Email already in use' }
+    }
+    
+    return { success: false, error: 'Profile update failed. Please try again.' }
+  }
+}
+
+/**
+ * Update user password
+ * Requirements: 7.2, 7.3
+ */
+export async function updatePassword(
+  userId: string,
+  currentPassword: string,
+  newPassword: string
+): Promise<UpdatePasswordResult> {
+  try {
+    // Validate input
+    const validation = updatePasswordSchema.safeParse({ currentPassword, newPassword })
+    
+    if (!validation.success) {
+      const errors = validation.error.issues.map((issue) => issue.message).join(', ')
+      return { success: false, error: errors }
+    }
+
+    // Get user from database
+    const user = await prisma.user.findUnique({
+      where: { id: userId },
+    })
+
+    if (!user || !user.passwordHash) {
+      return { success: false, error: 'User not found' }
+    }
+
+    // Verify current password (Requirement 7.2)
+    const isCurrentPasswordValid = await bcrypt.compare(currentPassword, user.passwordHash)
+
+    if (!isCurrentPasswordValid) {
+      return { success: false, error: 'Current password is incorrect' }
+    }
+
+    // Hash new password (Requirement 7.3)
+    const newPasswordHash = await bcrypt.hash(newPassword, 10)
+
+    // Update password
+    await prisma.user.update({
+      where: { id: userId },
+      data: {
+        passwordHash: newPasswordHash,
+      },
+    })
+
+    return { success: true }
+  } catch (error) {
+    console.error('Password update error:', error)
+    return { success: false, error: 'Password update failed. Please try again.' }
+  }
+}
+
+/**
+ * Get user profile (without sensitive data)
+ * Requirement: 7.5 - Profile data exposure protection
+ */
+export async function getUserProfile(userId: string) {
+  try {
+    const user = await prisma.user.findUnique({
+      where: { id: userId },
+      select: {
+        id: true,
+        email: true,
+        name: true,
+        createdAt: true,
+        updatedAt: true,
+        // Explicitly exclude passwordHash (Requirement 7.5)
+      },
+    })
+
+    return user
+  } catch (error) {
+    console.error('Get user profile error:', error)
+    return null
+  }
+}