docs(aws): add terraform.tfvars.example and improve setup instructions

- Add terraform.tfvars.example with all required variables
- Update README.md to reference terraform.tfvars.example
- Add AWS account ID retrieval command
- Clarify required variables

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

workers/clawdbot-aws/terraform/README.md

@@ -25,16 +25,22 @@ aws secretsmanager get-secret-value --secret-id clawdbot/discord-token
 
 ### 2. Terraform変数の設定
 
-`.env.example`をコピーして`terraform.tfvars`を作成:
+`terraform.tfvars.example`をコピーして`terraform.tfvars`を作成:
 
 ```bash
-cp .env.example terraform.tfvars
+cp terraform.tfvars.example terraform.tfvars
 ```
 
 `terraform.tfvars`を編集して以下の値を設定:
-- `aws_account_id`: AWSアカウントID
+- `aws_account_id`: AWSアカウントID（13桁の数字）
 - `discord_token_secret_name`: Secrets Managerのシークレット名（デフォルト: `clawdbot/discord-token`）
 
+**重要**: `aws_account_id`は必須です。AWSコンソールまたは以下のコマンドで確認できます:
+
+```bash
+aws sts get-caller-identity --query Account --output text
+```
+
 ### 3. Terraformの実行
 
 ```bash

workers/clawdbot-aws/terraform/terraform.tfvars.example

@@ -0,0 +1,34 @@
+# AWS Terraform Variables for Clawdbot ECS Fargate Deployment
+# Copy this file to terraform.tfvars and fill in the values
+
+# AWS Configuration
+aws_region        = "ap-northeast-1"
+aws_account_id    = "123456789012"  # Your AWS account ID
+
+# Environment
+environment       = "production"
+project_name      = "clawdbot"
+
+# ECS Configuration
+ecs_task_cpu            = 256   # 0.25 vCPU
+ecs_task_memory         = 2048  # 2 GB
+ecs_service_desired_count = 1
+
+# Discord Token (DEPRECATED - Use Secrets Manager instead)
+# discord_token = "your_bot_token_here"  # DO NOT use in production
+
+# Secrets Manager Secret Name for Discord Bot Token
+discord_token_secret_name = "clawdbot/discord-token"
+# Create the secret in AWS Secrets Manager before running Terraform:
+# aws secretsmanager create-secret \
+#   --name clawdbot/discord-token \
+#   --description "Discord Bot Token for Clawdbot" \
+#   --secret-string "your_bot_token_here"
+
+# DynamoDB Tables
+sessions_table_name     = "clawdbot-sessions"
+artifacts_table_name    = "clawdbot-artifacts"
+
+# S3 Bucket
+artifacts_bucket_name   = "clawdbot-artifacts"
+artifacts_bucket_ttl_days = 7