feat: add support for awscli

[chenrui333]

Summary

Please add native support for aws/awscli commands in RTK.

AWS CLI output is often very verbose (large JSON payloads, multi-resource listings, progress noise), so it burns a lot of LLM context compared to the actual signal.

High-value commands (phase 1)

• aws s3 ls
• aws s3 cp
• aws s3 sync
• aws ec2 describe-instances
• aws logs tail
• aws cloudformation describe-stacks
• aws ecs describe-services
• aws eks list-clusters / aws eks describe-cluster

Expected behavior

• On success: compact summaries (counts/resources/status) instead of full payloads.
• On failure: preserve clear error code/message and actionable stderr.
• For unsupported subcommands: safe passthrough (rtk aws ... still works without dropping output correctness).
• Keep command semantics unchanged (output compaction only).

Why this fits current RTK architecture

Current code already has this pattern for infra commands:

• command routing in src/main.rs
• infra filters in src/container.rs (docker / kubectl)
• auto-rewrite integration in .claude/hooks/rtk-rewrite.sh
• discover classification in src/discover/registry.rs

aws appears to be currently uncovered in rewrite/discover, so it remains an unhandled high-volume command family.

Implementation sketch

1. Add src/aws_cmd.rs for rtk aws ....
2. Wire a new Aws command in src/main.rs.
3. Add rewrite rule in .claude/hooks/rtk-rewrite.sh (aws ... -> rtk aws ...).
4. Add discover rule in src/discover/registry.rs so aws is recognized as supported.
5. Add tests + README examples.

Acceptance criteria

• rtk aws ... supports at least the phase-1 commands above.
• Token reduction is measurable on verbose AWS commands (target: 70%+).
• Error paths remain actionable.
• Hook and discover integration included.

[pszymkowiak]

Fixed in v0.30.0 — dedicated Rust module for AWS CLI (s3, ec2, logs, etc.). Tested locally: rtk aws s3 ls works correctly.