chore(skills): add git-state verification warning to pr-push skill

Sprint 30 showed that grepping source files does not distinguish
committed code from uncommitted agent work. Added mandatory
git status + git diff --stat check from repo root before accepting
"already done" claims, and a warning about CWD path resolution.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.claude/skills/pr-push/SKILL.md

@@ -66,8 +66,22 @@ works on screen before invoking `/pr-push`. If they haven't, ask:
 
 ```bash
 git status
+git diff --stat
 ```
 
+**Run both commands from the repo root** (`git rev-parse --show-toplevel`).
+Running from a subdirectory can cause paths to not resolve, hiding real
+changes — Sprint 30 proved this when `git diff HEAD -- server/src/bin/atlas.rs`
+returned 0 lines from the wrong CWD, masking uncommitted agent work.
+
+**CRITICAL: Do not trust "already done" claims without checking git state.**
+If agents report that work was "already implemented in a prior commit," verify
+by checking `git status` and `git diff --stat` first. Grepping source files
+only proves the code exists on disk — it does NOT prove the code is committed.
+Uncommitted working-tree changes look identical to committed code when you
+read files. Only `git status` distinguishes "already shipped" from "just
+written by a teammate."
+
 If there are uncommitted changes (staged or unstaged), run the **commit skill**
 first. Use the `/git-commit` skill to group changes into logical commits with
 proper conventional commit messages. Wait for commit to complete before