fix(discover): normalize venv/absolute paths with binary preservation (#1053)

[Timber125]

Summary

Fixes the path-prefixed command rewrite issue described in #1053 and #1206.

The naive approach (strip .venv/bin/ prefix and emit bare rtk pytest) changes execution semantics: handlers call resolved_command("pytest") which resolves via PATH, not the original venv binary. When the venv isn't activated, this executes the wrong binary or fails.

This PR implements the three-part fix from #1053:

1. Normalize for matching only — strip_absolute_path() in rewrite_segment_inner() normalizes path-prefixed commands to find the matching registry rule, but doesn't discard the original path
2. Preserve original binary via RTK_BIN_PATH — when a path prefix is stripped, the rewritten command includes RTK_BIN_PATH=<original_bin> as an env var prefix (e.g. RTK_BIN_PATH=.venv/bin/python rtk pytest tests/)
3. Handlers honor the override — override_command() in utils.rs checks RTK_BIN_PATH; if the basename starts with "python", it uses -m <tool> module invocation, otherwise direct execution. All Python handlers (pytest, ruff, mypy, pip) use this before falling back to PATH resolution.

Paths handled

Input	Rewritten
.venv/bin/pytest tests/	RTK_BIN_PATH=.venv/bin/pytest rtk pytest tests/
.venv/bin/python -m pytest tests/	RTK_BIN_PATH=.venv/bin/python rtk pytest tests/
/usr/bin/grep -rn pattern src/	RTK_BIN_PATH=/usr/bin/grep rtk grep -rn pattern src/
pytest tests/ (no path)	rtk pytest tests/ (no RTK_BIN_PATH)

Test plan

• All 1606 existing tests pass
• New test: bare commands produce no RTK_BIN_PATH
• Updated tests: venv paths emit correct RTK_BIN_PATH values
• cargo fmt --all && cargo clippy --all-targets && cargo test --all clean

Closes #1053
Refs #1206

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[pszymkowiak]

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📊 Automated PR Analysis

🐛 Type	bug-fix
🟢 Risk	low

Summary

Fixes a bug where commands invoked via absolute or virtualenv paths (e.g., .venv/bin/python -m pytest) were correctly classified but not rewritten to their rtk equivalents. The root cause was that rewrite_segment_inner() did not call strip_absolute_path() before prefix matching, unlike classify_command(). The fix is a 2-line insertion to normalize paths before the rewrite loop.

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.

[Timber125]

⚠️ Converting to draft — this fix is naive and hits exactly the wrong-binary trap described in #1053.

Problem: Normalizing .venv/bin/pytest → pytest in rewrite output means rtk pytest calls resolved_command("pytest") which resolves via PATH, not the original venv binary. If the venv isn't activated, this executes the wrong binary or fails.

Reworking to implement the three-part fix from #1053:

1. Normalize in rewrite_segment() for matching only
2. Preserve the original executable path via RTK_ORIGINAL_BIN env var
3. Teach handlers to honor the explicit binary override

Will reopen when ready.