fix(ls): preserve .env in default output

[nghiahsgs]

Problem

.env is listed in NOISE_DIRS (src/cmds/system/constants.rs), so rtk ls silently drops it unless the agent passes -a. This creates a data-loss hazard:

1. Agent runs rtk ls to scan a project's setup state.
2. Output shows .env.example but no .env.
3. Agent concludes the project isn't configured and writes a fresh .env from the template.
4. Real production secrets (DB passwords, API keys) are clobbered.

A user reproduced this directly:

$ touch .env
$ rtk ls
.claude/
demo-agents/
README.md  2.6K
notes.md  19.0K
slides.md  31.1K
Summary: 3 files, 2 dirs (3 .md)

.env is gone from the output. The agent has no way to know it exists.

Why this matters

.env is configuration the agent must reason about, not a build artifact like node_modules/, .git/, or target/. The other entries in NOISE_DIRS are regenerable; .env typically is not.

CONTRIBUTING.md's Correctness VS Token Savings principle applies directly:

When in doubt, preserve correctness.

A few tokens for one filename are cheap. Restoring rotated production credentials is not.

Fix

Remove .env from NOISE_DIRS. Sibling entries .env.local, .env.production, .env.example were never matched (the filter uses exact equality), so behavior for those is unchanged — they were already visible. This change only restores .env itself.

Test

Adds test_compact_preserves_dotenv covering .env, .env.local, and .env.example to lock in the expected behavior.

running 19 tests
test result: ok. 19 passed; 0 failed

Scope

Intentionally narrow. Does not touch:

• env, .venv, venv (Python virtualenv directories — those are regenerable)
• The broader question of whether any dotfile filtering belongs in ls (see fix(ls): fix empty output on non-English locales, hidden file leaking, and egg-info glob #810)
• RTK_DISABLED / --raw discussions (feat(hooks): add RTK_DISABLED=1 env var to bypass all hooks #1167, feat(cli): add --raw flag for unfiltered command output #1171)

Just .env. One line in constants, one regression test.

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[pszymkowiak]

[w] wshm · Automated triage by AI

📊 Automated PR Analysis

🐛 Type	bug-fix
🟢 Risk	low

Summary

Removes .env from the NOISE_DIRS list so that rtk ls no longer silently hides .env files in its default output. This prevents agents from mistakenly concluding a project is unconfigured and overwriting real .env files containing production secrets. A regression test is added to lock in the corrected behavior.

Review Checklist

• Tests present
• Breaking change
• Docs updated

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Analyzed automatically by wshm · This is an automated analysis, not a human review.