fix(git): re-insert -- separator when clap consumes it from git diff args (#1215)

[ousamabenyounes]

Summary

Fixes #1215

• Adds normalize_diff_args() which re-inserts -- before the first path-like argument when clap's trailing_var_arg = true silently consumed it
• Adds looks_like_path() heuristic: args containing /, \, or starting with ./~ are treated as paths
• No-op when -- is already present — so rtk git diff HEAD -- file (where clap preserves the separator) is unaffected

Root cause

clap's trailing_var_arg = true treats -- as the option terminator and drops it when it appears as the first positional argument. Result:

rtk git diff -- apps/.../MyComponent.tsx
  → args = ["apps/.../MyComponent.tsx"]   # -- was consumed
  → git diff --stat apps/.../MyComponent.tsx
  → fatal: ambiguous argument 'apps/...': unknown revision or path

The fix normalises args at the start of run_diff before any git command is built.

Test plan

• cargo fmt --all && cargo clippy --all-targets && cargo test --all
• 7 new unit tests for normalize_diff_args: no-op, path-with-slash, ref+path, flag+path, pure-flags, dotfile, bare-ref
• 1380 tests pass (baseline: 1373), 0 regressions

Files changed

File	Change
src/cmds/git/git.rs	Add looks_like_path, normalize_diff_args, call in run_diff, 7 tests

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[pszymkowiak]

[w] wshm · Automated triage by AI

📊 Automated PR Analysis

🐛 Type	bug-fix
🟡 Risk	medium

Summary

Fixes a bug where clap's trailing_var_arg silently consumes the -- separator in git diff args, causing git to misinterpret file paths as revisions. Also fixes a secondary issue where user-format git log output was being incorrectly truncated, corrupting programmatic output like SHA hashes.

Review Checklist

• Tests present
• Breaking change
• Docs updated

Linked issues: #1215

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

[FlorianBruniaux]

LGTM — clean fix, tests pass.