fix(aws): honor explicit --output json/yaml losslessly

[maxmilian]

Summary

• Fixes aws lambda commands: rtk corrupts --output json (returns non-JSON schema skeleton, drops field values) #2139: rtk aws ... --output json returned a lossy schema skeleton (string, int, string[64]) or a one-line table summary instead of valid JSON, dropping field values (ImageUri, CodeSha256, env vars) and breaking downstream jq / json.load.
• Root cause: rtk applied its summarizers (filter_lambda_get) or generic schema compression (filter_json_string) regardless of the user-requested output format.
• Fix: when the user explicitly requests a structured, parseable format (--output json / --output=json / yaml / yaml-stream), run() short-circuits to a new byte-faithful run_passthrough. Lossy/human formats (table, text) and the no-flag default keep the existing compression behavior.

This covers all aws subcommands, not just lambda.

Test plan

• cargo fmt --all clean
• cargo clippy --all-targets — zero warnings
• cargo test --all — 1947 passed
• New unit test test_explicit_lossless_format covers json/yaml/=json positives and table/text/absent negatives

🤖 Generated with Claude Code

[maxmilian]

Automated triage on #2139 (by wshm) independently confirms this: categorized as bug, priority high, 93% confidence, with the recommended fix being to "bypass summarization when an explicit output format flag is present" — which is exactly what this PR does.

This PR narrows that slightly: it only bypasses for parseable formats (json / yaml / yaml-stream) where losslessness is a contract, while keeping the existing compression for the human-readable table / text formats and the no-flag default — so token savings are preserved everywhere they don't break parsing.

[maxmilian]

Note for the PR Testing Checklist: the "token savings ≥60%" item is N/A here. This isn't a new/compressing filter — it's a correctness fix that bypasses compression when the user explicitly requests --output json/yaml. It directly applies design principle Correctness vs Token Savings: a flag that explicitly asks for parseable, lossless output must not be reformatted into a lossy summary/skeleton.

The remaining checklist items are covered:

• Unit tests added (test_explicit_lossless_format, incl. repeated/dangling --output)
• cargo fmt --all --check && cargo clippy --all-targets && cargo test — all green (1947 passed)
• Manual rtk aws ... --output json verified to pass through byte-for-byte

On security: the new run_passthrough forwards the user's args to the aws binary via Command::arg (no shell string interpolation), so it doesn't widen any injection surface versus the existing runners.

[dessite]

I believe I tackled this problem a bit differently a few hours earlier #2135 ;) rtk adds --output json on it's own if no --output defined afair