test(coat-338): Scenario A — sync-merge from sibling feature branch

[anto-deepsource]

End-to-end test for coat PR #338 — verifies that when HEAD on the PR becomes a 2-parent merge whose second parent is not on the base branch, coat now writes a non-empty full_diff.diff and the AI sees the merged-in content.

Topology after the next push:

master  ─── ...                                  (base branch)

P2-side ─── TYPO_COMMIT ─── FIX_COMMIT
                              ▲
                              │ merged in (P2)
                              │
feature ─── TYPO_COMMIT ─── M    (HEAD after next push)
                              ▲
                              │ P1 = local feature tip

Steps now in progress:

1. ✅ This push at HEAD = TYPO_COMMIT — triggers Analysis Update demo_code.py #1 (PR mode).
2. ⏳ After Analysis Update demo_code.py #1 finishes, push the sync-merge M — Analysis Remove debugger #2 (commit mode).
3. ⏳ Pull coat + enki logs from deepsource-dev; assert merge classification log line and that full_diff.diff is non-empty (vs. pre-fix behavior of writing empty diff).

DO NOT MERGE — test PR for tracking coat #338.

[deepsource-development]

DeepSource Code Review

We reviewed changes in 9d1323c...fa3c3b2 on this pull request. Below is the summary for the review, and you can see the individual issues we found as inline review comments.

See full review on DeepSource ↗

PR Report Card

Overall Grade

Security   Reliability   Complexity   Hygiene

Code Review Summary

Analyzer	Status	Updated (UTC)	Details
Python		May 26, 2026 8:39a.m.	Review ↗
Secrets		May 26, 2026 8:39a.m.	Review ↗