fix(rewrite): skip cat rewrite when incompatible flags present

[MauroDeryckere]

Summary

• Skip cat → rtk read rewrite when cat is invoked with flags that have different semantics than rtk read (e.g. -A, -v, -e, -t, -s, --show-all)
• Allow rewrite for cat -n since it maps correctly to rtk read -n (both mean line numbers)
• Plain cat file continues to rewrite to rtk read file as before

Problem

rtk rewrite blindly forwards all cat flags to rtk read. This causes incorrect behavior because the flags have different semantics:

Flag	cat meaning	rtk read meaning
-n	Line numbers	Line numbers (compatible)
-v	Show non-printing chars	Verbosity level (incompatible)
-A	Show all (non-printing + endings)	Not supported (fails)
-e	Show non-printing + $ at EOL	Not supported
-t	Show non-printing + tabs as ^I	Not supported
-s	Squeeze blank lines	Not supported

For example, cat -A file.cpp was rewritten to rtk read -A file.cpp which fails with rtk: Failed to resolve 'read' via PATH.

Fix

Early check in rewrite_segment(): if the command starts with cat and the first argument starts with - (but is not -n), return None to skip the rewrite. This follows the same pattern used for head -N and tail special cases.

Test plan

• New test test_rewrite_cat_with_incompatible_flags_skipped — verifies -A, -v, -e, -t, -s, --show-all all return None
• New test test_rewrite_cat_with_compatible_flags — verifies cat -n file.txt rewrites to rtk read -n file.txt
• Existing test_rewrite_cat_file still passes — plain cat file → rtk read file
• Full test suite: 1119 passed, 3 ignored

[pszymkowiak]

[w] wshm · Automated triage by AI

📊 Automated PR Analysis

🐛 Type	bug-fix
🟢 Risk	low

Summary

Fixes the cat-to-rtk-read rewrite to skip commands with incompatible flags (e.g., -A, -v, -e, -t, -s, --show-all) that have different semantics in rtk read, while still allowing the compatible -n flag. Previously, cat with unsupported flags was blindly rewritten, causing rtk read failures.

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.

[aeppling]

Hey

We are cleaning up the codebase and improving the project structure for better onboarding. As part of this effort, PR #826 reorganizes src/ from a flat layout into subfolders.

No logic changes — only file moves and import path updates.

What you need to do

Rebase your branch on develop when receiving this comment:

git fetch origin && git rebase origin/develop

Git detects renames automatically. If you get import conflicts, update the paths:

use crate::git;        // now: use crate::cmds::git::git;
use crate::tracking;   // now: use crate::core::tracking;
use crate::config;     // now: use crate::core::config;
use crate::init;       // now: use crate::hooks::init;
use crate::gain;       // now: use crate::analytics::gain;

Need help rebasing? Tag @aeppling