fix(agent): address review feedback on file modification tracking

[pablof7z]

Addresses review feedback on #116 (file modification tracking).

Blocking fixes

1. Eliminate duplicated resolve_path / expand_env_vars. file_modifications.rs carried local copies of both helpers that already live in tools/fs.rs (same crate). resolve_path is now pub(crate) in tools/fs.rs and imported via crate::tools::fs::resolve_path; the local copies are deleted. expand_env_vars stays private to fs.rs since it has no cross-module caller after the dedup.

2. Stop swallowing errors in render_reminder. The ConversationStore::open and get_file_snapshots_for_agent calls used .ok()?, which collapsed a real DB failure into the same None as "no snapshots." Both now log via tracing::warn! before returning None.

3. Distinguish unreadable from unchanged in render_file_block. std::fs::read(...).ok()? meant a deleted or unreadable file silently vanished from the report. A NotFound error now emits a "File was deleted." modification block (a deletion is itself an external change worth reporting); any other read error is logged; only a genuine hash match returns None.

Style fixes

• Collapsed multi-paragraph module/struct/function doc comments to a single line; dropped WHAT-only docs on trivial private fns (hash_bytes, parse_write_path), keeping only WHY comments.
• Removed the // ===…=== section banner this PR had added to store.rs (the record_file_snapshot doc already conveys the upsert behavior). Pre-existing banners elsewhere in store.rs were left untouched.

Verification

• cargo build -p tenex-agent — clean (no new warnings; deletion of the local helpers leaves no unused import)
• cargo test -p tenex-agent — 58 passed (incl. all 4 file_modifications tests)
• cargo test -p tenex-conversations — 19 passed

🤖 Generated with Claude Code

[claude]

Code Review

Overview

Clean follow-up to #116. All three blocking issues are correctly resolved: path-resolution deduplication, error logging in render_reminder, and deletion detection in render_file_block. The doc-comment trimming also aligns well with the project's only-WHY-comments rule.

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What is done well

Deduplication via pub(crate) — making resolve_path crate-visible in tools/fs.rs and importing it is the right fix. No wrapper, no re-export, just a single canonical implementation. expand_env_vars correctly stays private since it has no cross-module caller after the cleanup.

Error logging — replacing .ok()? with match … tracing::warn! in render_reminder means DB failures are now observable without changing the graceful-degradation behavior (returning None so the agent loop continues).

Deletion handling — NotFound in render_file_block now produces a real <file-modification> block rather than silently suppressing what is a meaningful external change. The three-way dispatch (deleted → Some(deletion), unreadable → logged + None, unchanged → None) is correct.

Comment reduction — dropping WHAT-only docs on hash_bytes, parse_write_path, and the section banner in store.rs is exactly right per the project conventions.

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Minor issues

1. No test for the deletion path (file_modifications.rs)

The new NotFound → deletion block branch is the most behaviorally interesting change here, and the diff shows no new test for it. The existing 4 tests are unchanged and almost certainly do not cover this case. Given how easy it is to test — write a snapshot, delete the file, call render_reminder — this is worth adding before merge to prevent future regression.

2. render_file_block doc comment is slightly stale (file_modifications.rs:141)

The new single-line doc says: "Render a single <file-modification> block for a snapshot whose on-disk content differs from the recorded hash." The function now also renders a block when the file no longer exists, which does not involve hashing at all. A small wording tweak or dropping the doc entirely (the function name and signature are self-explanatory) would resolve this.

3. Long single-line doc on render_reminder (file_modifications.rs:93)

The collapsed doc runs well past 100 characters. Either split it at the or None clause or trim it further and let the function name carry the weight.

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Summary

No blocking issues. Fix 1 (missing test) is the most worth addressing before merge; the other two are nits. The core logic changes are correct and the codebase is cleaner after this PR.